diff --git a/java/com/google/gerrit/httpd/BUILD b/java/com/google/gerrit/httpd/BUILD
index d4045dd..4bd3e2e 100644
--- a/java/com/google/gerrit/httpd/BUILD
+++ b/java/com/google/gerrit/httpd/BUILD
@@ -33,11 +33,11 @@
         "//lib/auto:auto-value-annotations",
         "//lib/commons:codec",
         "//lib/commons:lang",
+        "//lib/flogger:api",
         "//lib/guice",
         "//lib/guice:guice-assistedinject",
         "//lib/guice:guice-servlet",
         "//lib/jgit/org.eclipse.jgit.http.server:jgit-servlet",
         "//lib/jgit/org.eclipse.jgit:jgit",
-        "//lib/log:api",
     ],
 )
diff --git a/java/com/google/gerrit/httpd/DirectChangeByCommit.java b/java/com/google/gerrit/httpd/DirectChangeByCommit.java
index 26e4198..152a83d 100644
--- a/java/com/google/gerrit/httpd/DirectChangeByCommit.java
+++ b/java/com/google/gerrit/httpd/DirectChangeByCommit.java
@@ -4,6 +4,7 @@
 
 import com.google.common.base.CharMatcher;
 import com.google.common.collect.ImmutableList;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.extensions.api.changes.Changes;
 import com.google.gerrit.extensions.common.ChangeInfo;
@@ -17,13 +18,12 @@
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 class DirectChangeByCommit extends HttpServlet {
   private static final long serialVersionUID = 1L;
-  private static final Logger log = LoggerFactory.getLogger(DirectChangeByCommit.class);
+
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final Changes changes;
 
@@ -39,7 +39,7 @@
     try {
       results = changes.query(query).withLimit(2).get();
     } catch (RestApiException e) {
-      log.warn("Cannot process query by URL: /r/" + query, e);
+      logger.atWarning().withCause(e).log("Cannot process query by URL: /r/%s", query);
       results = ImmutableList.of();
     }
     String token;
diff --git a/java/com/google/gerrit/httpd/HttpServletResponseRecorder.java b/java/com/google/gerrit/httpd/HttpServletResponseRecorder.java
index 6774ec80..397d093 100644
--- a/java/com/google/gerrit/httpd/HttpServletResponseRecorder.java
+++ b/java/com/google/gerrit/httpd/HttpServletResponseRecorder.java
@@ -14,13 +14,12 @@
 
 package com.google.gerrit.httpd;
 
+import com.google.common.flogger.FluentLogger;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpServletResponseWrapper;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * HttpServletResponse wrapper to allow response status code override.
@@ -29,7 +28,7 @@
  * override the response http status code.
  */
 public class HttpServletResponseRecorder extends HttpServletResponseWrapper {
-  private static final Logger log = LoggerFactory.getLogger(HttpServletResponseRecorder.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
   private static final String LOCATION_HEADER = "Location";
 
   private int status;
@@ -78,7 +77,7 @@
 
   void play() throws IOException {
     if (status != 0) {
-      log.debug("Replaying {} {}", status, statusMsg);
+      logger.atFine().log("Replaying %s %s", status, statusMsg);
 
       if (status == SC_MOVED_TEMPORARILY) {
         super.sendRedirect(headers.get(LOCATION_HEADER));
diff --git a/java/com/google/gerrit/httpd/ProjectBasicAuthFilter.java b/java/com/google/gerrit/httpd/ProjectBasicAuthFilter.java
index 6174644..e7b35ec 100644
--- a/java/com/google/gerrit/httpd/ProjectBasicAuthFilter.java
+++ b/java/com/google/gerrit/httpd/ProjectBasicAuthFilter.java
@@ -19,6 +19,7 @@
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.client.GitBasicAuthPolicy;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.reviewdb.client.Account;
@@ -47,8 +48,6 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpServletResponseWrapper;
 import org.apache.commons.codec.binary.Base64;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Authenticates the current user by HTTP basic authentication.
@@ -62,7 +61,7 @@
  */
 @Singleton
 class ProjectBasicAuthFilter implements Filter {
-  private static final Logger log = LoggerFactory.getLogger(ProjectBasicAuthFilter.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   public static final String REALM_NAME = "Gerrit Code Review";
   private static final String AUTHORIZATION = "Authorization";
@@ -131,10 +130,11 @@
     Optional<AccountState> accountState =
         accountCache.getByUsername(username).filter(a -> a.getAccount().isActive());
     if (!accountState.isPresent()) {
-      log.warn(
-          "Authentication failed for "
-              + username
-              + ": account inactive or not provisioned in Gerrit");
+      logger
+          .atWarning()
+          .log(
+              "Authentication failed for %s: account inactive or not provisioned in Gerrit",
+              username);
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     }
@@ -163,17 +163,17 @@
       if (who.checkPassword(password, username)) {
         return succeedAuthentication(who);
       }
-      log.warn(authenticationFailedMsg(username, req), e);
+      logger.atWarning().withCause(e).log(authenticationFailedMsg(username, req));
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     } catch (AuthenticationFailedException e) {
       // This exception is thrown if the user provided wrong credentials, we don't need to log a
       // stacktrace for it.
-      log.warn(authenticationFailedMsg(username, req) + ": " + e.getMessage());
+      logger.atWarning().log(authenticationFailedMsg(username, req) + ": %s", e.getMessage());
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     } catch (AccountException e) {
-      log.warn(authenticationFailedMsg(username, req), e);
+      logger.atWarning().withCause(e).log(authenticationFailedMsg(username, req));
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     }
@@ -186,10 +186,11 @@
 
   private boolean failAuthentication(Response rsp, String username, HttpServletRequest req)
       throws IOException {
-    log.warn(
-        authenticationFailedMsg(username, req)
-            + ": password does not match the one stored in Gerrit",
-        username);
+    logger
+        .atWarning()
+        .log(
+            authenticationFailedMsg(username, req)
+                + ": password does not match the one stored in Gerrit");
     rsp.sendError(SC_UNAUTHORIZED);
     return false;
   }
diff --git a/java/com/google/gerrit/httpd/ProjectOAuthFilter.java b/java/com/google/gerrit/httpd/ProjectOAuthFilter.java
index 2b37378..c97c840 100644
--- a/java/com/google/gerrit/httpd/ProjectOAuthFilter.java
+++ b/java/com/google/gerrit/httpd/ProjectOAuthFilter.java
@@ -21,6 +21,7 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
 import com.google.common.collect.Iterables;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.auth.oauth.OAuthLoginProvider;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.registration.DynamicMap;
@@ -54,8 +55,6 @@
 import javax.servlet.http.HttpServletResponseWrapper;
 import org.apache.commons.codec.binary.Base64;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Authenticates the current user with an OAuth2 server.
@@ -64,8 +63,7 @@
  */
 @Singleton
 class ProjectOAuthFilter implements Filter {
-
-  private static final Logger log = LoggerFactory.getLogger(ProjectOAuthFilter.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final String REALM_NAME = "Gerrit Code Review";
   private static final String AUTHORIZATION = "Authorization";
@@ -156,9 +154,11 @@
     Optional<AccountState> who =
         accountCache.getByUsername(authInfo.username).filter(a -> a.getAccount().isActive());
     if (!who.isPresent()) {
-      log.warn(
-          authenticationFailedMsg(authInfo.username, req)
-              + ": account inactive or not provisioned in Gerrit");
+      logger
+          .atWarning()
+          .log(
+              authenticationFailedMsg(authInfo.username, req)
+                  + ": account inactive or not provisioned in Gerrit");
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     }
@@ -179,7 +179,7 @@
       ws.setAccessPathOk(AccessPath.REST_API, true);
       return true;
     } catch (AccountException e) {
-      log.warn(authenticationFailedMsg(authInfo.username, req), e);
+      logger.atWarning().withCause(e).log(authenticationFailedMsg(authInfo.username, req));
       rsp.sendError(SC_UNAUTHORIZED);
       return false;
     }
diff --git a/java/com/google/gerrit/httpd/QueryDocumentationFilter.java b/java/com/google/gerrit/httpd/QueryDocumentationFilter.java
index 7a89b3b..8b82c00 100644
--- a/java/com/google/gerrit/httpd/QueryDocumentationFilter.java
+++ b/java/com/google/gerrit/httpd/QueryDocumentationFilter.java
@@ -16,6 +16,7 @@
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableListMultimap;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.httpd.restapi.RestApiServlet;
 import com.google.gerrit.server.documentation.QueryDocumentationExecutor;
 import com.google.gerrit.server.documentation.QueryDocumentationExecutor.DocQueryException;
@@ -32,12 +33,10 @@
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 public class QueryDocumentationFilter implements Filter {
-  private final Logger log = LoggerFactory.getLogger(QueryDocumentationFilter.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final QueryDocumentationExecutor searcher;
 
@@ -62,7 +61,7 @@
         List<DocResult> result = searcher.doQuery(request.getParameter("q"));
         RestApiServlet.replyJson(req, rsp, ImmutableListMultimap.of(), result);
       } catch (DocQueryException e) {
-        log.error("Doc search failed:", e);
+        logger.atSevere().withCause(e).log("Doc search failed");
         rsp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
       }
     } else {
diff --git a/java/com/google/gerrit/httpd/RunAsFilter.java b/java/com/google/gerrit/httpd/RunAsFilter.java
index 9940cd9..f3bf5af 100644
--- a/java/com/google/gerrit/httpd/RunAsFilter.java
+++ b/java/com/google/gerrit/httpd/RunAsFilter.java
@@ -18,6 +18,7 @@
 import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
 import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.reviewdb.client.Account;
@@ -41,13 +42,11 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.errors.ConfigInvalidException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /** Allows running a request as another user account. */
 @Singleton
 class RunAsFilter implements Filter {
-  private static final Logger log = LoggerFactory.getLogger(RunAsFilter.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
   private static final String RUN_AS = "X-Gerrit-RunAs";
 
   static class Module extends ServletModule {
@@ -99,7 +98,7 @@
         replyError(req, res, SC_FORBIDDEN, "not permitted to use " + RUN_AS, null);
         return;
       } catch (PermissionBackendException e) {
-        log.warn("cannot check runAs", e);
+        logger.atWarning().withCause(e).log("cannot check runAs");
         replyError(req, res, SC_INTERNAL_SERVER_ERROR, RUN_AS + " unavailable", null);
         return;
       }
@@ -108,7 +107,7 @@
       try {
         target = accountResolver.find(runas);
       } catch (OrmException | IOException | ConfigInvalidException e) {
-        log.warn("cannot resolve account for " + RUN_AS, e);
+        logger.atWarning().withCause(e).log("cannot resolve account for %s", RUN_AS);
         replyError(req, res, SC_INTERNAL_SERVER_ERROR, "cannot resolve " + RUN_AS, e);
         return;
       }
diff --git a/java/com/google/gerrit/httpd/WebSessionManager.java b/java/com/google/gerrit/httpd/WebSessionManager.java
index 8b6694c..3d2668b 100644
--- a/java/com/google/gerrit/httpd/WebSessionManager.java
+++ b/java/com/google/gerrit/httpd/WebSessionManager.java
@@ -29,6 +29,7 @@
 import static java.util.concurrent.TimeUnit.SECONDS;
 
 import com.google.common.cache.Cache;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.server.account.externalids.ExternalId;
 import com.google.gerrit.server.config.ConfigUtil;
@@ -43,11 +44,9 @@
 import java.security.SecureRandom;
 import java.util.concurrent.TimeUnit;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class WebSessionManager {
-  private static final Logger log = LoggerFactory.getLogger(WebSessionManager.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
   public static final String CACHE_NAME = "web_sessions";
 
   private final long sessionMaxAgeMillis;
@@ -69,10 +68,11 @@
                 SECONDS.convert(MAX_AGE_MINUTES, MINUTES),
                 SECONDS));
     if (sessionMaxAgeMillis < MINUTES.toMillis(5)) {
-      log.warn(
-          String.format(
+      logger
+          .atWarning()
+          .log(
               "cache.%s.maxAge is set to %d milliseconds; it should be at least 5 minutes.",
-              CACHE_NAME, sessionMaxAgeMillis));
+              CACHE_NAME, sessionMaxAgeMillis);
     }
   }
 
diff --git a/java/com/google/gerrit/httpd/auth/container/HttpLoginServlet.java b/java/com/google/gerrit/httpd/auth/container/HttpLoginServlet.java
index d86c85a..515d694 100644
--- a/java/com/google/gerrit/httpd/auth/container/HttpLoginServlet.java
+++ b/java/com/google/gerrit/httpd/auth/container/HttpLoginServlet.java
@@ -17,6 +17,7 @@
 import static com.google.gerrit.server.account.externalids.ExternalId.SCHEME_EXTERNAL;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.httpd.CanonicalWebUrl;
@@ -40,8 +41,6 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.errors.ConfigInvalidException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
@@ -56,7 +55,7 @@
 @Singleton
 class HttpLoginServlet extends HttpServlet {
   private static final long serialVersionUID = 1L;
-  private static final Logger log = LoggerFactory.getLogger(HttpLoginServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final DynamicItem<WebSession> webSession;
   private final CanonicalWebUrl urlProvider;
@@ -86,10 +85,12 @@
     CacheHeaders.setNotCacheable(rsp);
     final String user = authFilter.getRemoteUser(req);
     if (user == null || "".equals(user)) {
-      log.error(
-          "Unable to authenticate user by "
-              + authFilter.getLoginHeader()
-              + " request header.  Check container or server configuration.");
+      logger
+          .atSevere()
+          .log(
+              "Unable to authenticate user by %s request header."
+                  + " Check container or server configuration.",
+              authFilter.getLoginHeader());
 
       final Document doc =
           HtmlDomUtil.parseFile( //
@@ -118,7 +119,7 @@
     try {
       arsp = accountManager.authenticate(areq);
     } catch (AccountException e) {
-      log.error("Unable to authenticate user \"" + user + "\"", e);
+      logger.atSevere().withCause(e).log("Unable to authenticate user \"%s\"", user);
       rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
       return;
     }
@@ -126,16 +127,17 @@
     String remoteExternalId = authFilter.getRemoteExternalIdToken(req);
     if (remoteExternalId != null) {
       try {
-        log.debug("Associating external identity \"{}\" to user \"{}\"", remoteExternalId, user);
+        logger
+            .atFine()
+            .log("Associating external identity \"%s\" to user \"%s\"", remoteExternalId, user);
         updateRemoteExternalId(arsp, remoteExternalId);
       } catch (AccountException | OrmException | ConfigInvalidException e) {
-        log.error(
-            "Unable to associate external identity \""
-                + remoteExternalId
-                + "\" to user \""
-                + user
-                + "\"",
-            e);
+        logger
+            .atSevere()
+            .withCause(e)
+            .log(
+                "Unable to associate external identity \"%s\" to user \"%s\"",
+                remoteExternalId, user);
         rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
         return;
       }
diff --git a/java/com/google/gerrit/httpd/auth/container/HttpsClientSslCertAuthFilter.java b/java/com/google/gerrit/httpd/auth/container/HttpsClientSslCertAuthFilter.java
index 534e50ec..40807c0 100644
--- a/java/com/google/gerrit/httpd/auth/container/HttpsClientSslCertAuthFilter.java
+++ b/java/com/google/gerrit/httpd/auth/container/HttpsClientSslCertAuthFilter.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.httpd.auth.container;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.httpd.WebSession;
 import com.google.gerrit.server.account.AccountException;
@@ -32,14 +33,12 @@
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 class HttpsClientSslCertAuthFilter implements Filter {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final Pattern REGEX_USERID = Pattern.compile("CN=([^,]*)");
-  private static final Logger log = LoggerFactory.getLogger(HttpsClientSslCertAuthFilter.class);
 
   private final DynamicItem<WebSession> webSession;
   private final AccountManager accountManager;
@@ -77,7 +76,7 @@
       arsp = accountManager.authenticate(areq);
     } catch (AccountException e) {
       String err = "Unable to authenticate user \"" + userName + "\"";
-      log.error(err, e);
+      logger.atSevere().withCause(e).log(err);
       throw new ServletException(err, e);
     }
     webSession.get().login(arsp, true);
diff --git a/java/com/google/gerrit/httpd/auth/ldap/LdapLoginServlet.java b/java/com/google/gerrit/httpd/auth/ldap/LdapLoginServlet.java
index 4671475..6370476 100644
--- a/java/com/google/gerrit/httpd/auth/ldap/LdapLoginServlet.java
+++ b/java/com/google/gerrit/httpd/auth/ldap/LdapLoginServlet.java
@@ -18,6 +18,7 @@
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.httpd.CanonicalWebUrl;
@@ -41,8 +42,6 @@
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
@@ -50,7 +49,7 @@
 @SuppressWarnings("serial")
 @Singleton
 class LdapLoginServlet extends HttpServlet {
-  private static final Logger log = LoggerFactory.getLogger(LdapLoginServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final AccountManager accountManager;
   private final DynamicItem<WebSession> webSession;
@@ -130,15 +129,15 @@
     } catch (AuthenticationFailedException e) {
       // This exception is thrown if the user provided wrong credentials, we don't need to log a
       // stacktrace for it.
-      log.warn("'{}' failed to sign in: {}", username, e.getMessage());
+      logger.atWarning().log("'%s' failed to sign in: %s", username, e.getMessage());
       sendForm(req, res, "Invalid username or password.");
       return;
     } catch (AccountException e) {
-      log.warn("'{}' failed to sign in", username, e);
+      logger.atWarning().withCause(e).log("'%s' failed to sign in", username);
       sendForm(req, res, "Authentication failed.");
       return;
     } catch (RuntimeException e) {
-      log.error("LDAP authentication failed", e);
+      logger.atSevere().withCause(e).log("LDAP authentication failed");
       sendForm(req, res, "Authentication unavailable at this time.");
       return;
     }
diff --git a/java/com/google/gerrit/httpd/auth/oauth/BUILD b/java/com/google/gerrit/httpd/auth/oauth/BUILD
index aa63f0d..96726ad 100644
--- a/java/com/google/gerrit/httpd/auth/oauth/BUILD
+++ b/java/com/google/gerrit/httpd/auth/oauth/BUILD
@@ -15,9 +15,9 @@
         "//lib:gwtorm",
         "//lib:servlet-api-3_1",
         "//lib/commons:codec",
+        "//lib/flogger:api",
         "//lib/guice",
         "//lib/guice:guice-servlet",
         "//lib/jgit/org.eclipse.jgit:jgit",
-        "//lib/log:api",
     ],
 )
diff --git a/java/com/google/gerrit/httpd/auth/oauth/OAuthSession.java b/java/com/google/gerrit/httpd/auth/oauth/OAuthSession.java
index 68b28a9d..866aaa0 100644
--- a/java/com/google/gerrit/httpd/auth/oauth/OAuthSession.java
+++ b/java/com/google/gerrit/httpd/auth/oauth/OAuthSession.java
@@ -18,6 +18,7 @@
 
 import com.google.common.base.CharMatcher;
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.auth.oauth.OAuthServiceProvider;
 import com.google.gerrit.extensions.auth.oauth.OAuthToken;
 import com.google.gerrit.extensions.auth.oauth.OAuthUserInfo;
@@ -47,13 +48,12 @@
 import javax.servlet.http.HttpServletResponse;
 import org.apache.commons.codec.binary.Base64;
 import org.eclipse.jgit.errors.ConfigInvalidException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @SessionScoped
 /* OAuth protocol implementation */
 class OAuthSession {
-  private static final Logger log = LoggerFactory.getLogger(OAuthSession.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private static final SecureRandom randomState = newRandomGenerator();
   private final String state;
   private final DynamicItem<WebSession> webSession;
@@ -93,7 +93,7 @@
   boolean login(
       HttpServletRequest request, HttpServletResponse response, OAuthServiceProvider oauth)
       throws IOException {
-    log.debug("Login " + this);
+    logger.atFine().log("Login %s", this);
 
     if (isOAuthFinal(request)) {
       if (!checkState(request)) {
@@ -101,19 +101,19 @@
         return false;
       }
 
-      log.debug("Login-Retrieve-User " + this);
+      logger.atFine().log("Login-Retrieve-User %s", this);
       OAuthToken token = oauth.getAccessToken(new OAuthVerifier(request.getParameter("code")));
       user = oauth.getUserInfo(token);
 
       if (isLoggedIn()) {
-        log.debug("Login-SUCCESS " + this);
+        logger.atFine().log("Login-SUCCESS %s", this);
         authenticateAndRedirect(request, response, token);
         return true;
       }
       response.sendError(SC_UNAUTHORIZED);
       return false;
     }
-    log.debug("Login-PHASE1 " + this);
+    logger.atFine().log("Login-PHASE1 %s", this);
     redirectToken = request.getRequestURI();
     // We are here in content of filter.
     // Due to this Jetty limitation:
@@ -148,7 +148,7 @@
       accountId = arsp.getAccountId();
       tokenCache.put(accountId, token);
     } catch (AccountException e) {
-      log.error("Unable to authenticate user \"" + user + "\"", e);
+      logger.atSevere().withCause(e).log("Unable to authenticate user \"%s\"", user);
       rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
       return;
     }
@@ -169,40 +169,33 @@
     if (claimedId.isPresent() && actualId.isPresent()) {
       if (claimedId.get().equals(actualId.get())) {
         // Both link to the same account, that's what we expected.
-        log.debug("OAuth2: claimed identity equals current id");
+        logger.atFine().log("OAuth2: claimed identity equals current id");
       } else {
         // This is (for now) a fatal error. There are two records
         // for what might be the same user.
         //
-        log.error(
-            "OAuth accounts disagree over user identity:\n"
-                + "  Claimed ID: "
-                + claimedId.get()
-                + " is "
-                + claimedIdentifier
-                + "\n"
-                + "  Delgate ID: "
-                + actualId.get()
-                + " is "
-                + user.getExternalId());
+        logger
+            .atSevere()
+            .log(
+                "OAuth accounts disagree over user identity:\n"
+                    + "  Claimed ID: %s is %s\n"
+                    + "  Delgate ID: %s is %s",
+                claimedId.get(), claimedIdentifier, actualId.get(), user.getExternalId());
         rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
         return false;
       }
     } else if (claimedId.isPresent() && !actualId.isPresent()) {
       // Claimed account already exists: link to it.
       //
-      log.info("OAuth2: linking claimed identity to {}", claimedId.get().toString());
+      logger.atInfo().log("OAuth2: linking claimed identity to %s", claimedId.get().toString());
       try {
         accountManager.link(claimedId.get(), req);
       } catch (OrmException | ConfigInvalidException e) {
-        log.error(
-            "Cannot link: "
-                + user.getExternalId()
-                + " to user identity:\n"
-                + "  Claimed ID: "
-                + claimedId.get()
-                + " is "
-                + claimedIdentifier);
+        logger
+            .atSevere()
+            .log(
+                "Cannot link: %s to user identity:\n  Claimed ID: %s is %s",
+                user.getExternalId(), claimedId.get(), claimedIdentifier);
         rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
         return false;
       }
@@ -215,11 +208,11 @@
     try {
       accountManager.link(identifiedUser.get().getAccountId(), areq);
     } catch (OrmException | ConfigInvalidException e) {
-      log.error(
-          "Cannot link: "
-              + user.getExternalId()
-              + " to user identity: "
-              + identifiedUser.get().getAccountId());
+      logger
+          .atSevere()
+          .log(
+              "Cannot link: %s to user identity: %s",
+              user.getExternalId(), identifiedUser.get().getAccountId());
       rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
       return false;
     } finally {
@@ -241,7 +234,7 @@
   private boolean checkState(ServletRequest request) {
     String s = Strings.nullToEmpty(request.getParameter("state"));
     if (!s.equals(state)) {
-      log.error("Illegal request state '" + s + "' on OAuthProtocol " + this);
+      logger.atSevere().log("Illegal request state '%s' on OAuthProtocol %s", s, this);
       return false;
     }
     return true;
diff --git a/java/com/google/gerrit/httpd/auth/openid/BUILD b/java/com/google/gerrit/httpd/auth/openid/BUILD
index 44b7bd1..9c48832 100644
--- a/java/com/google/gerrit/httpd/auth/openid/BUILD
+++ b/java/com/google/gerrit/httpd/auth/openid/BUILD
@@ -17,10 +17,10 @@
         "//lib:gwtorm",
         "//lib:servlet-api-3_1",
         "//lib/commons:codec",
+        "//lib/flogger:api",
         "//lib/guice",
         "//lib/guice:guice-servlet",
         "//lib/jgit/org.eclipse.jgit:jgit",
-        "//lib/log:api",
         "//lib/openid:consumer",
     ],
 )
diff --git a/java/com/google/gerrit/httpd/auth/openid/LoginForm.java b/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
index 6090fed..adf6458 100644
--- a/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
+++ b/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
@@ -20,6 +20,7 @@
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.common.auth.openid.OpenIdUrls;
@@ -47,8 +48,6 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
@@ -56,7 +55,8 @@
 @SuppressWarnings("serial")
 @Singleton
 class LoginForm extends HttpServlet {
-  private static final Logger log = LoggerFactory.getLogger(LoginForm.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private static final ImmutableMap<String, String> ALL_PROVIDERS =
       ImmutableMap.of(
           "launchpad", OpenIdUrls.URL_LAUNCHPAD,
@@ -91,7 +91,7 @@
     this.oauthServiceProviders = oauthServiceProviders;
 
     if (urlProvider == null || Strings.isNullOrEmpty(urlProvider.get())) {
-      log.error("gerrit.canonicalWebUrl must be set in gerrit.config");
+      logger.atSevere().log("gerrit.canonicalWebUrl must be set in gerrit.config");
     }
 
     if (authConfig.getAuthType() == AuthType.OPENID_SSO) {
@@ -160,14 +160,14 @@
       mode = SignInMode.SIGN_IN;
     }
 
-    log.debug("mode \"{}\"", mode);
+    logger.atFine().log("mode \"%s\"", mode);
     OAuthServiceProvider oauthProvider = lookupOAuthServiceProvider(id);
 
     if (oauthProvider == null) {
-      log.debug("OpenId provider \"{}\"", id);
+      logger.atFine().log("OpenId provider \"%s\"", id);
       discover(req, res, link, id, remember, token, mode);
     } else {
-      log.debug("OAuth provider \"{}\"", id);
+      logger.atFine().log("OAuth provider \"%s\"", id);
       OAuthSessionOverOpenID oauthSession = oauthSessionProvider.get();
       if (!currentUserProvider.get().isIdentifiedUser() && oauthSession.isLoggedIn()) {
         oauthSession.logout();
diff --git a/java/com/google/gerrit/httpd/auth/openid/OAuthSessionOverOpenID.java b/java/com/google/gerrit/httpd/auth/openid/OAuthSessionOverOpenID.java
index 878f9ee..1cc43be 100644
--- a/java/com/google/gerrit/httpd/auth/openid/OAuthSessionOverOpenID.java
+++ b/java/com/google/gerrit/httpd/auth/openid/OAuthSessionOverOpenID.java
@@ -17,6 +17,7 @@
 import static javax.servlet.http.HttpServletResponse.SC_UNAUTHORIZED;
 
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.auth.oauth.OAuthServiceProvider;
 import com.google.gerrit.extensions.auth.oauth.OAuthToken;
 import com.google.gerrit.extensions.auth.oauth.OAuthUserInfo;
@@ -45,14 +46,13 @@
 import javax.servlet.http.HttpServletResponse;
 import org.apache.commons.codec.binary.Base64;
 import org.eclipse.jgit.errors.ConfigInvalidException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /** OAuth protocol implementation */
 @SessionScoped
 class OAuthSessionOverOpenID {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   static final String GERRIT_LOGIN = "/login";
-  private static final Logger log = LoggerFactory.getLogger(OAuthSessionOverOpenID.class);
   private static final SecureRandom randomState = newRandomGenerator();
   private final String state;
   private final DynamicItem<WebSession> webSession;
@@ -89,7 +89,7 @@
   boolean login(
       HttpServletRequest request, HttpServletResponse response, OAuthServiceProvider oauth)
       throws IOException {
-    log.debug("Login " + this);
+    logger.atFine().log("Login %s", this);
 
     if (isOAuthFinal(request)) {
       if (!checkState(request)) {
@@ -97,19 +97,19 @@
         return false;
       }
 
-      log.debug("Login-Retrieve-User " + this);
+      logger.atFine().log("Login-Retrieve-User %s", this);
       token = oauth.getAccessToken(new OAuthVerifier(request.getParameter("code")));
       user = oauth.getUserInfo(token);
 
       if (isLoggedIn()) {
-        log.debug("Login-SUCCESS " + this);
+        logger.atFine().log("Login-SUCCESS %s", this);
         authenticateAndRedirect(request, response);
         return true;
       }
       response.sendError(SC_UNAUTHORIZED);
       return false;
     }
-    log.debug("Login-PHASE1 " + this);
+    logger.atFine().log("Login-PHASE1 %s", this);
     redirectToken = LoginUrlToken.getToken(request);
     response.sendRedirect(oauth.getAuthorizationUrl() + "&state=" + state);
     return false;
@@ -135,50 +135,43 @@
       if (!Strings.isNullOrEmpty(claimedIdentifier)) {
         claimedId = accountManager.lookup(claimedIdentifier);
         if (!claimedId.isPresent()) {
-          log.debug("Claimed identity is unknown");
+          logger.atFine().log("Claimed identity is unknown");
         }
       }
 
       // Use case 1: claimed identity was provided during handshake phase
       // and user account exists for this identity
       if (claimedId.isPresent()) {
-        log.debug("Claimed identity is set and is known");
+        logger.atFine().log("Claimed identity is set and is known");
         if (actualId.isPresent()) {
           if (claimedId.get().equals(actualId.get())) {
             // Both link to the same account, that's what we expected.
-            log.debug("Both link to the same account. All is fine.");
+            logger.atFine().log("Both link to the same account. All is fine.");
           } else {
             // This is (for now) a fatal error. There are two records
             // for what might be the same user. The admin would have to
             // link the accounts manually.
-            log.error(
-                "OAuth accounts disagree over user identity:\n"
-                    + "  Claimed ID: "
-                    + claimedId.get()
-                    + " is "
-                    + claimedIdentifier
-                    + "\n"
-                    + "  Delgate ID: "
-                    + actualId.get()
-                    + " is "
-                    + user.getExternalId());
+            logger
+                .atFine()
+                .log(
+                    "OAuth accounts disagree over user identity:\n"
+                        + "  Claimed ID: %s is %s\n"
+                        + "  Delgate ID: %s is %s",
+                    claimedId.get(), claimedIdentifier, actualId.get(), user.getExternalId());
             rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
             return;
           }
         } else {
           // Claimed account already exists: link to it.
-          log.debug("Claimed account already exists: link to it.");
+          logger.atFine().log("Claimed account already exists: link to it.");
           try {
             accountManager.link(claimedId.get(), areq);
           } catch (OrmException | ConfigInvalidException e) {
-            log.error(
-                "Cannot link: "
-                    + user.getExternalId()
-                    + " to user identity:\n"
-                    + "  Claimed ID: "
-                    + claimedId.get()
-                    + " is "
-                    + claimedIdentifier);
+            logger
+                .atSevere()
+                .log(
+                    "Cannot link: %s to user identity:\n  Claimed ID: %s is %s",
+                    user.getExternalId(), claimedId.get(), claimedIdentifier);
             rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
             return;
           }
@@ -187,10 +180,12 @@
         // Use case 2: link mode activated from the UI
         Account.Id accountId = identifiedUser.get().getAccountId();
         try {
-          log.debug("Linking \"{}\" to \"{}\"", user.getExternalId(), accountId);
+          logger.atFine().log("Linking \"%s\" to \"%s\"", user.getExternalId(), accountId);
           accountManager.link(accountId, areq);
         } catch (OrmException | ConfigInvalidException e) {
-          log.error("Cannot link: " + user.getExternalId() + " to user identity: " + accountId);
+          logger
+              .atSevere()
+              .log("Cannot link: %s to user identity: %s", user.getExternalId(), accountId);
           rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
           return;
         } finally {
@@ -202,7 +197,7 @@
       areq.setDisplayName(user.getDisplayName());
       arsp = accountManager.authenticate(areq);
     } catch (AccountException e) {
-      log.error("Unable to authenticate user \"" + user + "\"", e);
+      logger.atSevere().withCause(e).log("Unable to authenticate user \"%s\"", user);
       rsp.sendError(HttpServletResponse.SC_FORBIDDEN);
       return;
     }
@@ -223,7 +218,7 @@
   private boolean checkState(ServletRequest request) {
     String s = Strings.nullToEmpty(request.getParameter("state"));
     if (!s.equals(state)) {
-      log.error("Illegal request state '" + s + "' on OAuthProtocol " + this);
+      logger.atSevere().log("Illegal request state '%s' on OAuthProtocol %s", s, this);
       return false;
     }
     return true;
diff --git a/java/com/google/gerrit/httpd/auth/openid/OpenIdServiceImpl.java b/java/com/google/gerrit/httpd/auth/openid/OpenIdServiceImpl.java
index a971fc3..4664e3b 100644
--- a/java/com/google/gerrit/httpd/auth/openid/OpenIdServiceImpl.java
+++ b/java/com/google/gerrit/httpd/auth/openid/OpenIdServiceImpl.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.httpd.auth.openid;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.common.auth.openid.OpenIdUrls;
 import com.google.gerrit.extensions.registration.DynamicItem;
@@ -64,12 +65,10 @@
 import org.openid4java.message.sreg.SRegRequest;
 import org.openid4java.message.sreg.SRegResponse;
 import org.openid4java.util.HttpClientFactory;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 class OpenIdServiceImpl {
-  private static final Logger log = LoggerFactory.getLogger(OpenIdServiceImpl.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   static final String RETURN_URL = "OpenID";
 
@@ -151,7 +150,7 @@
     final AuthRequest aReq;
     try {
       aReq = manager.authenticate(state.discovered, state.retTo.toString());
-      log.debug("OpenID: openid-realm={}", state.contextUrl);
+      logger.atFine().log("OpenID: openid-realm=%s", state.contextUrl);
       aReq.setRealm(state.contextUrl);
 
       if (requestRegistration(aReq)) {
@@ -173,7 +172,7 @@
         aReq.addExtension(pape);
       }
     } catch (MessageException | ConsumerException e) {
-      log.error("Cannot create OpenID redirect for " + openidIdentifier, e);
+      logger.atSevere().withCause(e).log("Cannot create OpenID redirect for %s" + openidIdentifier);
       return new DiscoveryResult(DiscoveryResult.Status.ERROR);
     }
 
@@ -195,7 +194,7 @@
     try {
       return accountManager.lookup(aReq.getIdentity()) == null;
     } catch (AccountException e) {
-      log.warn("Cannot determine if user account exists", e);
+      logger.atWarning().withCause(e).log("Cannot determine if user account exists");
       return true;
     }
   }
@@ -250,17 +249,18 @@
       if ("Nonce verification failed.".equals(result.getStatusMsg())) {
         // We might be suffering from clock skew on this system.
         //
-        log.error(
-            "OpenID failure: "
-                + result.getStatusMsg()
-                + "  Likely caused by clock skew on this server,"
-                + " install/configure NTP.");
+        logger
+            .atSevere()
+            .log(
+                "OpenID failure: %s  Likely caused by clock skew on this server,"
+                    + " install/configure NTP.",
+                result.getStatusMsg());
         cancelWithError(req, rsp, result.getStatusMsg());
 
       } else if (result.getStatusMsg() != null) {
         // Authentication failed.
         //
-        log.error("OpenID failure: " + result.getStatusMsg());
+        logger.atSevere().log("OpenID failure: %s", result.getStatusMsg());
         cancelWithError(req, rsp, result.getStatusMsg());
 
       } else {
@@ -286,12 +286,12 @@
         // right now. Instead of blocking all of them log the error and
         // let the authentication complete anyway.
         //
-        log.error("Invalid PAPE response " + openidIdentifier + ": " + err);
+        logger.atSevere().log("Invalid PAPE response %s: %s", openidIdentifier, err);
         unsupported = true;
         ext = null;
       }
       if (!unsupported && ext == null) {
-        log.error("No PAPE extension response from " + openidIdentifier);
+        logger.atSevere().log("No PAPE extension response from %s", openidIdentifier);
         cancelWithError(req, rsp, "OpenID provider does not support PAPE.");
         return;
       }
@@ -354,7 +354,7 @@
         }
 
         if (!match) {
-          log.error("Domain disallowed: " + emailDomain);
+          logger.atSevere().log("Domain disallowed: %s", emailDomain);
           cancelWithError(req, rsp, "Domain disallowed");
           return;
         }
@@ -376,17 +376,13 @@
           // This is (for now) a fatal error. There are two records
           // for what might be the same user.
           //
-          log.error(
-              "OpenID accounts disagree over user identity:\n"
-                  + "  Claimed ID: "
-                  + claimedId.get()
-                  + " is "
-                  + claimedIdentifier
-                  + "\n"
-                  + "  Delgate ID: "
-                  + actualId.get()
-                  + " is "
-                  + areq.getExternalIdKey());
+          logger
+              .atSevere()
+              .log(
+                  "OpenID accounts disagree over user identity:\n"
+                      + "  Claimed ID: %s is %s\n"
+                      + "  Delgate ID: %s is %s",
+                  claimedId.get(), claimedIdentifier, actualId.get(), areq.getExternalIdKey());
           cancelWithError(req, rsp, "Contact site administrator");
           return;
         }
@@ -451,7 +447,7 @@
           }
       }
     } catch (AccountException e) {
-      log.error("OpenID authentication failure", e);
+      logger.atSevere().withCause(e).log("OpenID authentication failure");
       cancelWithError(req, rsp, "Contact site administrator");
     }
   }
@@ -531,7 +527,7 @@
     try {
       list = manager.discover(openidIdentifier);
     } catch (DiscoveryException e) {
-      log.error("Cannot discover OpenID " + openidIdentifier, e);
+      logger.atSevere().withCause(e).log("Cannot discover OpenID %s", openidIdentifier);
       return null;
     }
     if (list == null || list.isEmpty()) {
diff --git a/java/com/google/gerrit/httpd/gitweb/GitwebServlet.java b/java/com/google/gerrit/httpd/gitweb/GitwebServlet.java
index cc22d24..383efd3 100644
--- a/java/com/google/gerrit/httpd/gitweb/GitwebServlet.java
+++ b/java/com/google/gerrit/httpd/gitweb/GitwebServlet.java
@@ -34,6 +34,7 @@
 
 import com.google.common.base.CharMatcher;
 import com.google.common.base.Splitter;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -85,14 +86,12 @@
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Repository;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /** Invokes {@code gitweb.cgi} for the project given in {@code p}. */
 @SuppressWarnings("serial")
 @Singleton
 class GitwebServlet extends HttpServlet {
-  private static final Logger log = LoggerFactory.getLogger(GitwebServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final String PROJECT_LIST_ACTION = "project_list";
 
@@ -137,7 +136,7 @@
       try {
         uri = new URI(url);
       } catch (URISyntaxException e) {
-        log.error("Invalid gitweb.url: " + url);
+        logger.atSevere().log("Invalid gitweb.url: %s", url);
       }
       gitwebUrl = uri;
     } else {
@@ -428,7 +427,7 @@
       sendErrorOrRedirect(req, rsp, HttpServletResponse.SC_NOT_FOUND);
       return;
     } catch (IOException | PermissionBackendException err) {
-      log.error("cannot load " + name, err);
+      logger.atSevere().withCause(err).log("cannot load %s", name);
       rsp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
       return;
     } catch (ResourceConflictException e) {
@@ -528,13 +527,13 @@
 
       final int status = proc.exitValue();
       if (0 != status) {
-        log.error("Non-zero exit status (" + status + ") from " + gitwebCgi);
+        logger.atSevere().log("Non-zero exit status (%d) from %s", status, gitwebCgi);
         if (!rsp.isCommitted()) {
           rsp.sendError(500);
         }
       }
     } catch (InterruptedException ie) {
-      log.debug("CGI: interrupted waiting for CGI to terminate");
+      logger.atFine().log("CGI: interrupted waiting for CGI to terminate");
     }
   }
 
@@ -659,7 +658,7 @@
                   dst.close();
                 }
               } catch (IOException e) {
-                log.error("Unexpected error copying input to CGI", e);
+                logger.atSevere().withCause(e).log("Unexpected error copying input to CGI");
               }
             },
             "Gitweb-InputFeeder")
@@ -679,9 +678,9 @@
                   }
                   b.append("CGI: ").append(line);
                 }
-                log.error(b.toString());
+                logger.atSevere().log(b.toString());
               } catch (IOException e) {
-                log.error("Unexpected error copying stderr from CGI", e);
+                logger.atSevere().withCause(e).log("Unexpected error copying stderr from CGI");
               }
             },
             "Gitweb-ErrorLogger")
diff --git a/java/com/google/gerrit/httpd/init/BUILD b/java/com/google/gerrit/httpd/init/BUILD
index f240088..292ceff 100644
--- a/java/com/google/gerrit/httpd/init/BUILD
+++ b/java/com/google/gerrit/httpd/init/BUILD
@@ -27,10 +27,10 @@
         "//lib:guava",
         "//lib:gwtorm",
         "//lib:servlet-api-3_1",
+        "//lib/flogger:api",
         "//lib/guice",
         "//lib/guice:guice-servlet",
         "//lib/jgit/org.eclipse.jgit:jgit",
-        "//lib/log:api",
         "//prolog:gerrit-prolog-common",
     ],
 )
diff --git a/java/com/google/gerrit/httpd/init/SiteInitializer.java b/java/com/google/gerrit/httpd/init/SiteInitializer.java
index 17a95b5..de4f284 100644
--- a/java/com/google/gerrit/httpd/init/SiteInitializer.java
+++ b/java/com/google/gerrit/httpd/init/SiteInitializer.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.httpd.init;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.pgm.init.BaseInit;
 import com.google.gerrit.pgm.init.PluginsDistribution;
 import java.nio.file.Path;
@@ -23,11 +24,9 @@
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.List;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public final class SiteInitializer {
-  private static final Logger LOG = LoggerFactory.getLogger(SiteInitializer.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final String sitePath;
   private final String initPath;
@@ -49,7 +48,7 @@
     try {
       if (sitePath != null) {
         Path site = Paths.get(sitePath);
-        LOG.info("Initializing site at " + site.toRealPath().normalize());
+        logger.atInfo().log("Initializing site at %s", site.toRealPath().normalize());
         new BaseInit(site, false, true, pluginsDistribution, pluginsToInstall).run();
         return;
       }
@@ -60,7 +59,7 @@
           site = Paths.get(initPath);
         }
         if (site != null) {
-          LOG.info("Initializing site at " + site.toRealPath().normalize());
+          logger.atInfo().log("Initializing site at %s", site.toRealPath().normalize());
           new BaseInit(
                   site,
                   new ReviewDbDataSourceProvider(),
@@ -72,7 +71,7 @@
         }
       }
     } catch (Exception e) {
-      LOG.error("Site init failed", e);
+      logger.atSevere().withCause(e).log("Site init failed");
       throw new RuntimeException(e);
     }
   }
diff --git a/java/com/google/gerrit/httpd/init/WebAppInitializer.java b/java/com/google/gerrit/httpd/init/WebAppInitializer.java
index 690d1ac..728fcd9 100644
--- a/java/com/google/gerrit/httpd/init/WebAppInitializer.java
+++ b/java/com/google/gerrit/httpd/init/WebAppInitializer.java
@@ -18,6 +18,7 @@
 import static com.google.inject.Stage.PRODUCTION;
 
 import com.google.common.base.Splitter;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.elasticsearch.ElasticIndexModule;
 import com.google.gerrit.extensions.client.AuthType;
 import com.google.gerrit.gpg.GpgModule;
@@ -127,12 +128,10 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.sql.DataSource;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /** Configures the web application environment for Gerrit Code Review. */
 public class WebAppInitializer extends GuiceServletContextListener implements Filter {
-  private static final Logger log = LoggerFactory.getLogger(WebAppInitializer.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private Path sitePath;
   private Injector dbInjector;
@@ -194,7 +193,7 @@
           buf.append("\nResolve above errors before continuing.");
           buf.append("\nComplete stack trace follows:");
         }
-        log.error(buf.toString(), first.getCause());
+        logger.atSevere().withCause(first.getCause()).log(buf.toString());
         throw new CreationException(Collections.singleton(first));
       }
 
diff --git a/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java b/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
index eb75a97..adb5516 100644
--- a/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
+++ b/java/com/google/gerrit/httpd/plugins/HttpPluginServlet.java
@@ -32,6 +32,7 @@
 import com.google.common.cache.Cache;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.io.ByteStreams;
 import com.google.common.net.HttpHeaders;
 import com.google.gerrit.extensions.registration.RegistrationHandle;
@@ -92,14 +93,13 @@
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.util.IO;
 import org.eclipse.jgit.util.RawParseUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 class HttpPluginServlet extends HttpServlet implements StartPluginListener, ReloadPluginListener {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private static final int SMALL_RESOURCE = 128 * 1024;
   private static final long serialVersionUID = 1L;
-  private static final Logger log = LoggerFactory.getLogger(HttpPluginServlet.class);
 
   private final MimeUtilFileTypeRegistry mimeUtil;
   private final Provider<String> webUrl;
@@ -191,7 +191,7 @@
       try {
         filter = plugin.getHttpInjector().getInstance(GuiceFilter.class);
       } catch (RuntimeException e) {
-        log.warn("Plugin {} cannot load GuiceFilter", name, e);
+        logger.atWarning().withCause(e).log("Plugin %s cannot load GuiceFilter", name);
         return null;
       }
 
@@ -199,7 +199,7 @@
         ServletContext ctx = PluginServletContext.create(plugin, wrapper.getFullPath(name));
         filter.init(new WrappedFilterConfig(ctx));
       } catch (ServletException e) {
-        log.warn("Plugin {} failed to initialize HTTP", name, e);
+        logger.atWarning().withCause(e).log("Plugin %s failed to initialize HTTP", name);
         return null;
       }
 
@@ -423,12 +423,12 @@
               && (name.endsWith(".md") || name.endsWith(".html"))
               && size.isPresent()) {
             if (size.get() <= 0 || size.get() > SMALL_RESOURCE) {
-              log.warn(
-                  "Plugin {}: {} omitted from document index. Size {} out of range (0,{}).",
-                  pluginName,
-                  name.substring(prefix.length()),
-                  size.get(),
-                  SMALL_RESOURCE);
+              logger
+                  .atWarning()
+                  .log(
+                      "Plugin %s: %s omitted from document index. "
+                          + "Size %d out of range (0,%d).",
+                      pluginName, name.substring(prefix.length()), size.get(), SMALL_RESOURCE);
               return false;
             }
             return true;
@@ -450,10 +450,11 @@
         if (about == null) {
           about = entry;
         } else {
-          log.warn(
-              "Plugin {}: Multiple 'about' documents found; using {}",
-              pluginName,
-              about.getName().substring(prefix.length()));
+          logger
+              .atWarning()
+              .log(
+                  "Plugin %s: Multiple 'about' documents found; using %s",
+                  pluginName, about.getName().substring(prefix.length()));
         }
       } else {
         docs.add(entry);
@@ -731,7 +732,10 @@
         }
         return def;
       } catch (IOException e) {
-        log.warn("Error getting {} for plugin {}, using default", attr, plugin.getName(), e);
+        logger
+            .atWarning()
+            .withCause(e)
+            .log("Error getting %s for plugin %s, using default", attr, plugin.getName());
         return null;
       }
     }
diff --git a/java/com/google/gerrit/httpd/plugins/LfsPluginServlet.java b/java/com/google/gerrit/httpd/plugins/LfsPluginServlet.java
index a8a8502..0ee22fa 100644
--- a/java/com/google/gerrit/httpd/plugins/LfsPluginServlet.java
+++ b/java/com/google/gerrit/httpd/plugins/LfsPluginServlet.java
@@ -18,6 +18,7 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static javax.servlet.http.HttpServletResponse.SC_NOT_IMPLEMENTED;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.extensions.registration.RegistrationHandle;
 import com.google.gerrit.httpd.resources.Resource;
 import com.google.gerrit.server.config.GerritServerConfig;
@@ -45,14 +46,14 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Singleton
 public class LfsPluginServlet extends HttpServlet
     implements StartPluginListener, ReloadPluginListener {
   private static final long serialVersionUID = 1L;
-  private static final Logger log = LoggerFactory.getLogger(LfsPluginServlet.class);
+
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private static final String MESSAGE_LFS_NOT_CONFIGURED =
       "{\"message\":\"No LFS plugin is configured to handle LFS requests.\"}";
 
@@ -139,7 +140,7 @@
       try {
         guiceFilter = plugin.getHttpInjector().getInstance(GuiceFilter.class);
       } catch (RuntimeException e) {
-        log.warn("Plugin {} cannot load GuiceFilter", name, e);
+        logger.atWarning().withCause(e).log("Plugin %s cannot load GuiceFilter", name);
         return null;
       }
 
@@ -147,7 +148,7 @@
         ServletContext ctx = PluginServletContext.create(plugin, "/");
         guiceFilter.init(new WrappedFilterConfig(ctx));
       } catch (ServletException e) {
-        log.warn("Plugin {} failed to initialize HTTP", name, e);
+        logger.atWarning().withCause(e).log("Plugin %s failed to initialize HTTP", name);
         return null;
       }
 
diff --git a/java/com/google/gerrit/httpd/plugins/PluginServletContext.java b/java/com/google/gerrit/httpd/plugins/PluginServletContext.java
index 8f64d9f..6a8ef32 100644
--- a/java/com/google/gerrit/httpd/plugins/PluginServletContext.java
+++ b/java/com/google/gerrit/httpd/plugins/PluginServletContext.java
@@ -15,6 +15,7 @@
 package com.google.gerrit.httpd.plugins;
 
 import com.google.common.collect.Maps;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Version;
 import com.google.gerrit.server.plugins.Plugin;
 import java.io.InputStream;
@@ -29,11 +30,9 @@
 import javax.servlet.RequestDispatcher;
 import javax.servlet.Servlet;
 import javax.servlet.ServletContext;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 class PluginServletContext {
-  private static final Logger log = LoggerFactory.getLogger(PluginServletContext.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   static ServletContext create(Plugin plugin, String contextPath) {
     return (ServletContext)
@@ -155,7 +154,7 @@
 
     @Override
     public void log(String msg, Throwable reason) {
-      log.warn("[plugin {}] {}", plugin.getName(), msg, reason);
+      logger.atWarning().withCause(reason).log("[plugin %s] %s", plugin.getName(), msg);
     }
 
     @Override
diff --git a/java/com/google/gerrit/httpd/raw/BazelBuild.java b/java/com/google/gerrit/httpd/raw/BazelBuild.java
index f52792c..92a5aaa 100644
--- a/java/com/google/gerrit/httpd/raw/BazelBuild.java
+++ b/java/com/google/gerrit/httpd/raw/BazelBuild.java
@@ -19,6 +19,7 @@
 
 import com.google.common.base.Joiner;
 import com.google.common.escape.Escaper;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.html.HtmlEscapers;
 import com.google.common.io.ByteStreams;
 import com.google.gerrit.common.TimeUtil;
@@ -33,11 +34,9 @@
 import java.util.Properties;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.util.RawParseUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class BazelBuild {
-  private static final Logger log = LoggerFactory.getLogger(BazelBuild.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final Path sourceRoot;
 
@@ -49,7 +48,7 @@
   public void build(Label label) throws IOException, BuildFailureException {
     ProcessBuilder proc = newBuildProcess(label);
     proc.directory(sourceRoot.toFile()).redirectErrorStream(true);
-    log.info("building " + label.fullName());
+    logger.atInfo().log("building %s", label.fullName());
     long start = TimeUtil.nowMs();
     Process rebuild = proc.start();
     byte[] out;
@@ -67,12 +66,12 @@
           "interrupted waiting for: " + Joiner.on(' ').join(proc.command()));
     }
     if (status != 0) {
-      log.warn("build failed: " + new String(out, UTF_8));
+      logger.atWarning().log("build failed: %s", new String(out, UTF_8));
       throw new BuildFailureException(out);
     }
 
     long time = TimeUtil.nowMs() - start;
-    log.info(String.format("UPDATED    %s in %.3fs", label.fullName(), time / 1000.0));
+    logger.atInfo().log("UPDATED    %s in %.3fs", label.fullName(), time / 1000.0);
   }
 
   // Represents a label in bazel.
diff --git a/java/com/google/gerrit/httpd/raw/HostPageServlet.java b/java/com/google/gerrit/httpd/raw/HostPageServlet.java
index ffecf1b..74868d7 100644
--- a/java/com/google/gerrit/httpd/raw/HostPageServlet.java
+++ b/java/com/google/gerrit/httpd/raw/HostPageServlet.java
@@ -18,6 +18,7 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.hash.Hasher;
 import com.google.common.hash.Hashing;
 import com.google.common.primitives.Bytes;
@@ -60,8 +61,6 @@
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
@@ -70,7 +69,7 @@
 @SuppressWarnings("serial")
 @Singleton
 public class HostPageServlet extends HttpServlet {
-  private static final Logger log = LoggerFactory.getLogger(HostPageServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final String HPD_ID = "gerrit_hostpagedata";
   private static final int DEFAULT_JS_LOAD_TIMEOUT = 5000;
@@ -141,7 +140,7 @@
         }
         src += "?content=" + md.hash().toString();
       } else {
-        log.debug("No " + src + " in webapp root; keeping noncache.js URL");
+        logger.atFine().log("No %s in webapp root; keeping noncache.js URL", src);
       }
     } catch (IOException e) {
       throw new IOException("Failed reading " + src, e);
@@ -173,7 +172,7 @@
         page = p;
       }
     } catch (IOException e) {
-      log.error("Cannot refresh site header/footer", e);
+      logger.atSevere().withCause(e).log("Cannot refresh site header/footer");
     }
     return p;
   }
@@ -225,7 +224,7 @@
         | ConfigInvalidException
         | IOException
         | PermissionBackendException e) {
-      log.warn("Cannot query account diff preferences", e);
+      logger.atWarning().withCause(e).log("Cannot query account diff preferences");
     }
     return DiffPreferencesInfo.defaults();
   }
diff --git a/java/com/google/gerrit/httpd/raw/ResourceServlet.java b/java/com/google/gerrit/httpd/raw/ResourceServlet.java
index 3ec6bdb..035653d 100644
--- a/java/com/google/gerrit/httpd/raw/ResourceServlet.java
+++ b/java/com/google/gerrit/httpd/raw/ResourceServlet.java
@@ -30,6 +30,7 @@
 import com.google.common.base.CharMatcher;
 import com.google.common.cache.Cache;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.hash.Hashing;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.httpd.HtmlDomUtil;
@@ -47,8 +48,6 @@
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Base class for serving static resources.
@@ -58,7 +57,7 @@
 public abstract class ResourceServlet extends HttpServlet {
   private static final long serialVersionUID = 1L;
 
-  private static final Logger log = LoggerFactory.getLogger(ResourceServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final int CACHE_FILE_SIZE_LIMIT_BYTES = 100 << 10;
 
@@ -161,7 +160,7 @@
         r = cache.get(p, newLoader(p));
       }
     } catch (ExecutionException e) {
-      log.warn("Cannot load static resource {}", req.getPathInfo(), e);
+      logger.atWarning().withCause(e).log("Cannot load static resource %s", req.getPathInfo());
       CacheHeaders.setNotCacheable(rsp);
       rsp.setStatus(SC_INTERNAL_SERVER_ERROR);
       return;
@@ -214,12 +213,12 @@
     try {
       Path p = getResourcePath(name);
       if (p == null) {
-        log.warn("Path doesn't exist {}", name);
+        logger.atWarning().log("Path doesn't exist %s", name);
         return null;
       }
       return cache.get(p, newLoader(p));
     } catch (ExecutionException | IOException e) {
-      log.warn("Cannot load static resource {}", name, e);
+      logger.atWarning().withCause(e).log("Cannot load static resource %s", name);
       return null;
     }
   }
diff --git a/java/com/google/gerrit/httpd/raw/StaticModule.java b/java/com/google/gerrit/httpd/raw/StaticModule.java
index 915e9ed..06ec799 100644
--- a/java/com/google/gerrit/httpd/raw/StaticModule.java
+++ b/java/com/google/gerrit/httpd/raw/StaticModule.java
@@ -21,6 +21,7 @@
 
 import com.google.common.cache.Cache;
 import com.google.common.collect.ImmutableList;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.extensions.client.UiType;
 import com.google.gerrit.httpd.XsrfCookieFilter;
@@ -57,11 +58,9 @@
 import javax.servlet.http.HttpServletRequestWrapper;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class StaticModule extends ServletModule {
-  private static final Logger log = LoggerFactory.getLogger(StaticModule.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   public static final String CACHE = "static_content";
   public static final String GERRIT_UI_COOKIE = "GERRIT_UI";
@@ -184,7 +183,7 @@
         if (exists(configPath) && isReadable(configPath)) {
           return new SingleFileServlet(cache, configPath, true);
         }
-        log.warn("Cannot read httpd.robotsFile, using default");
+        logger.atWarning().log("Cannot read httpd.robotsFile, using default");
       }
       Paths p = getPaths();
       if (p.warFs != null) {
diff --git a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
index 913128e..4c9a035 100644
--- a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
+++ b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
@@ -58,6 +58,7 @@
 import com.google.common.collect.Iterables;
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.Lists;
+import com.google.common.flogger.FluentLogger;
 import com.google.common.io.BaseEncoding;
 import com.google.common.io.CountingOutputStream;
 import com.google.common.math.IntMath;
@@ -164,12 +165,11 @@
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.util.TemporaryBuffer;
 import org.eclipse.jgit.util.TemporaryBuffer.Heap;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class RestApiServlet extends HttpServlet {
   private static final long serialVersionUID = 1L;
-  private static final Logger log = LoggerFactory.getLogger(RestApiServlet.class);
+
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   /** MIME type used for a JSON response body. */
   private static final String JSON_TYPE = "application/json";
@@ -1192,7 +1192,7 @@
     if (!Strings.isNullOrEmpty(req.getQueryString())) {
       uri += "?" + req.getQueryString();
     }
-    log.error("Error in {} {}", req.getMethod(), uri, err);
+    logger.atSevere().withCause(err).log("Error in %s %s", req.getMethod(), uri);
 
     if (!res.isCommitted()) {
       res.reset();
diff --git a/java/com/google/gerrit/httpd/rpc/GerritJsonServlet.java b/java/com/google/gerrit/httpd/rpc/GerritJsonServlet.java
index e787a48..f5d2216 100644
--- a/java/com/google/gerrit/httpd/rpc/GerritJsonServlet.java
+++ b/java/com/google/gerrit/httpd/rpc/GerritJsonServlet.java
@@ -16,6 +16,7 @@
 
 import com.google.common.collect.ListMultimap;
 import com.google.common.collect.MultimapBuilder;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.audit.Audit;
 import com.google.gerrit.common.auth.SignInRequired;
@@ -38,13 +39,12 @@
 import java.lang.reflect.Method;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /** Base JSON servlet to ensure the current user is not forged. */
 @SuppressWarnings("serial")
 final class GerritJsonServlet extends JsonServlet<GerritJsonServlet.GerritCall> {
-  private static final Logger log = LoggerFactory.getLogger(GerritJsonServlet.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
   private static final ThreadLocal<GerritCall> currentCall = new ThreadLocal<>();
   private static final ThreadLocal<MethodHandle> currentMethod = new ThreadLocal<>();
   private final DynamicItem<WebSession> session;
@@ -141,7 +141,7 @@
                 result));
       }
     } catch (Throwable all) {
-      log.error("Unable to log the call", all);
+      logger.atSevere().withCause(all).log("Unable to log the call");
     }
   }
 
@@ -190,7 +190,7 @@
         declaredField = clazz.getDeclaredField(fieldName);
         declaredField.setAccessible(true);
       } catch (Exception e) {
-        log.error("Unable to expose RPS/JSON result field");
+        logger.atSevere().log("Unable to expose RPS/JSON result field");
       }
       return declaredField;
     }
@@ -205,9 +205,9 @@
         Method method = (Method) methodField.get(this.getMethod());
         return method.getDeclaringClass();
       } catch (IllegalArgumentException e) {
-        log.error("Cannot access result field");
+        logger.atSevere().log("Cannot access result field");
       } catch (IllegalAccessException e) {
-        log.error("No permissions to access result field");
+        logger.atSevere().log("No permissions to access result field");
       }
 
       return null;
@@ -222,9 +222,9 @@
       try {
         return resultField.get(this);
       } catch (IllegalArgumentException e) {
-        log.error("Cannot access result field");
+        logger.atSevere().log("Cannot access result field");
       } catch (IllegalAccessException e) {
-        log.error("No permissions to access result field");
+        logger.atSevere().log("No permissions to access result field");
       }
 
       return null;
diff --git a/java/com/google/gerrit/httpd/rpc/SystemInfoServiceImpl.java b/java/com/google/gerrit/httpd/rpc/SystemInfoServiceImpl.java
index 7a7713d..634e8d8 100644
--- a/java/com/google/gerrit/httpd/rpc/SystemInfoServiceImpl.java
+++ b/java/com/google/gerrit/httpd/rpc/SystemInfoServiceImpl.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.httpd.rpc;
 
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.data.SshHostKey;
 import com.google.gerrit.common.data.SystemInfoService;
 import com.google.gerrit.server.ssh.SshInfo;
@@ -26,11 +27,9 @@
 import java.util.ArrayList;
 import java.util.List;
 import javax.servlet.http.HttpServletRequest;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 class SystemInfoServiceImpl implements SystemInfoService {
-  private static final Logger log = LoggerFactory.getLogger(SystemInfoServiceImpl.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final JSch JSCH = new JSch();
 
@@ -63,7 +62,7 @@
     HttpServletRequest r = httpRequest.get();
     String ua = r.getHeader("User-Agent");
     message = message.replaceAll("\n", "\n  ");
-    log.error("Client UI JavaScript error: User-Agent=" + ua + ": " + message);
+    logger.atSevere().log("Client UI JavaScript error: User-Agent=%s: %s", ua, message);
     callback.onSuccess(VoidResult.INSTANCE);
   }
 }
diff --git a/java/com/google/gerrit/httpd/template/SiteHeaderFooter.java b/java/com/google/gerrit/httpd/template/SiteHeaderFooter.java
index dca4d0f..655f4ca 100644
--- a/java/com/google/gerrit/httpd/template/SiteHeaderFooter.java
+++ b/java/com/google/gerrit/httpd/template/SiteHeaderFooter.java
@@ -17,6 +17,7 @@
 import static com.google.gerrit.common.FileUtil.lastModified;
 
 import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.httpd.HtmlDomUtil;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.config.SitePaths;
@@ -25,14 +26,12 @@
 import java.io.IOException;
 import java.nio.file.Path;
 import org.eclipse.jgit.lib.Config;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
 @Singleton
 public class SiteHeaderFooter {
-  private static final Logger log = LoggerFactory.getLogger(SiteHeaderFooter.class);
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final boolean refreshHeaderFooter;
   private final SitePaths sitePaths;
@@ -48,7 +47,7 @@
       t.load();
       template = t;
     } catch (IOException e) {
-      log.warn("Cannot load site header or footer", e);
+      logger.atWarning().withCause(e).log("Cannot load site header or footer");
     }
   }
 
@@ -60,7 +59,7 @@
         t.load();
         template = t;
       } catch (IOException e) {
-        log.warn("Cannot refresh site header or footer", e);
+        logger.atWarning().withCause(e).log("Cannot refresh site header or footer");
         t = template;
       }
     }