diff --git a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/AMQProperties.java b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/AMQProperties.java
index bdc3a88..f38a9cc 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/AMQProperties.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/AMQProperties.java
@@ -63,8 +63,9 @@
               default:
                 break;
             }
-          } catch (Exception ex) {
-            LOGGER.info(ex.getMessage());
+          } catch (IllegalAccessException ex) {
+            LOGGER.warn("Cannot access field {}. Cause: {}",
+                f.getName(), ex.getMessage());
           }
         }
       }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/section/Sections.java b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/section/Sections.java
index b2361ac..759ef03 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/section/Sections.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/config/section/Sections.java
@@ -48,8 +48,9 @@
             f.set(section, Boolean.valueOf(a.value()));
           }
         }
-      } catch (Exception ex) {
-        LOGGER.warn("Exception during initialize: {}", f.getName());
+      } catch (IllegalAccessException ex) {
+        LOGGER.warn("Cannot access field {}. Cause: {}",
+            f.getName(), ex.getMessage());
       }
     }
     return section;
@@ -76,9 +77,9 @@
             config.setBoolean(getName(section), null, f.getName(), Boolean.class.cast(obj));
           }
         }
-      } catch (Exception ex) {
-        LOGGER.warn("Exception during toConfig: {}", f.getName());
-        LOGGER.info("{}", ex.getMessage());
+      } catch (IllegalAccessException ex) {
+        LOGGER.warn("Cannot access field {}. Cause: {}",
+            f.getName(), ex.getMessage());
       }
     }
     return config;
@@ -104,8 +105,9 @@
                 f.set(section, config.getBoolean(getName(section), null, f.getName(), false));
               }
             }
-          } catch (Exception ex) {
-            LOGGER.warn("Exception during fromConfig: {}", f.getName());
+          } catch (IllegalAccessException ex) {
+            LOGGER.warn("Cannot access field {}. Cause: {}",
+                f.getName(), ex.getMessage());
           }
         }
       }
@@ -131,9 +133,9 @@
             f.set(section, val);
           }
         }
-      } catch (Exception ex) {
-        LOGGER.warn("Exception during normalize: {}", f.getName());
-        LOGGER.info("{}", ex.getMessage());
+      } catch (IllegalAccessException ex) {
+        LOGGER.warn("Cannot access field {}. Cause: {}",
+            f.getName(), ex.getMessage());
       }
     }
     return section;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/session/type/AMQPSession.java b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/session/type/AMQPSession.java
index 0fa964b..1f9b7e3 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/session/type/AMQPSession.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/session/type/AMQPSession.java
@@ -34,6 +34,9 @@
 
 import java.io.IOException;
 import java.net.URISyntaxException;
+import java.security.KeyManagementException;
+import java.security.NoSuchAlgorithmException;
+import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicInteger;
 
 public final class AMQPSession implements Session {
@@ -118,8 +121,8 @@
         ch.addShutdownListener(channelListener);
         failureCount.set(0);
         LOGGER.info(MSG("Channel #{} opened."), ch.getChannelNumber());
-      } catch (Exception ex) {
-        LOGGER.warn(MSG("Failed to open channel."));
+      } catch (IOException ex) {
+        LOGGER.error(MSG("Failed to open channel."), ex);
         failureCount.incrementAndGet();
       }
       if (failureCount.get() > properties.getSection(Monitor.class).failureCount) {
@@ -155,9 +158,9 @@
     } catch (URISyntaxException ex) {
       LOGGER.error(MSG("URI syntax error: {}"), amqp.uri);
     } catch (IOException ex) {
-      LOGGER.error(MSG("Connection cannot be opened."));
-    } catch (Exception ex) {
-      LOGGER.warn(MSG("Connection has something error. it will be disposed."), ex);
+      LOGGER.error(MSG("Connection cannot be opened."), ex);
+    } catch (KeyManagementException | NoSuchAlgorithmException ex) {
+      LOGGER.error(MSG("Security error when opening connection."), ex);
     }
   }
 
@@ -166,22 +169,22 @@
     LOGGER.info(MSG("Disconnecting..."));
     try {
       if (channel != null) {
-        LOGGER.info(MSG("Close Channel #{}..."), channel.getChannelNumber());
+        LOGGER.info(MSG("Closing Channel #{}..."), channel.getChannelNumber());
         channel.close();
       }
-    } catch (Exception ex) {
-      LOGGER.warn(MSG("Error when close channel.") , ex);
+    } catch (IOException | TimeoutException ex) {
+      LOGGER.error(MSG("Error when closing channel."), ex);
     } finally {
       channel = null;
     }
 
     try {
       if (connection != null) {
-        LOGGER.info(MSG("Close Connection..."));
+        LOGGER.info(MSG("Closing Connection..."));
         connection.close();
       }
-    } catch (Exception ex) {
-      LOGGER.warn(MSG("Error when close connection.") , ex);
+    } catch (IOException ex) {
+      LOGGER.error(MSG("Error when closing connection."), ex);
     } finally {
       connection = null;
     }
@@ -196,12 +199,12 @@
       Message message = properties.getSection(Message.class);
       Exchange exchange = properties.getSection(Exchange.class);
       try {
-        LOGGER.debug(MSG("Send message."));
+        LOGGER.debug(MSG("Sending message."));
         channel.basicPublish(exchange.name, message.routingKey,
             properties.getAMQProperties().getBasicProperties(),
             messageBody.getBytes(CharEncoding.UTF_8));
-      } catch (Exception ex) {
-        LOGGER.warn(MSG("Error when sending meessage."), ex);
+      } catch (IOException ex) {
+        LOGGER.error(MSG("Error when sending meessage."), ex);
       }
     }
   }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/solver/version/V1.java b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/solver/version/V1.java
index 4a9cb9f..800f01b 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/solver/version/V1.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/rabbitmq/solver/version/V1.java
@@ -26,6 +26,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
+import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 
@@ -65,8 +66,8 @@
       Files.createDirectories(siteDir);
       Files.move(oldFile, newFile);
       Files.createFile(siteDir.resolve(DEFAULT_SITE_NAME + FILE_EXT));
-    } catch (Exception ex) {
-      LOGGER.info(ex.getMessage());
+    } catch (IOException ex) {
+      LOGGER.error("Failed to initialize plugin configuration", ex);
     }
   }
 }