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Posted to log4j-dev@logging.apache.org by "Michael Kloster (JIRA)" <ji...@apache.org> on 2013/07/11 09:33:48 UTC
[jira] [Commented] (LOG4J2-291) Failover appender doesn't fail over
on JDBC appender error
[ https://issues.apache.org/jira/browse/LOG4J2-291?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13705559#comment-13705559 ]
Michael Kloster commented on LOG4J2-291:
----------------------------------------
It seems to the the issue goes deeper than just the value of the handleExceptions flag. In the current trunk, the JDBCDatabaseManager writeInternal() method catches SQLExceptions, logs them, and does not throw them as AppenderRuntimeException. This code starts in JDBCDatabaseManager on line 117.
{code:title=JDBCDatabaseManager.java|borderStyle=solid}
117: } catch (final SQLException e) {
118: LOGGER.error("Failed to insert record for log event in manager [{}].", this.getName(), e);
119: } finally {
{code}
This means any exception in writing the log to the database gets trapped. I'm new to the Log4J 2 codebase, but it seems to me there should be an additional line after 118 to the effect of:
{code:title=JDBCDatabaseManager.java|borderStyle=solid}
} catch (final SQLException e) {
LOGGER.error("Failed to insert record for log event in manager [{}].", this.getName(), e);
throw new org.apache.logging.log4j.core.appender.AppenderRuntimeException(e);
} finally {
{code}
After making the change to JDBCAppender per Thomas N. comment and adding the throw above, I am able to get the failover logs appearing in the log file. The use case I used for testing a failure is to shutdown the database server after the application is running, thus simulating a database failure or connectivity problem.
Scanning through the rest of JDBCDatabaseManager seems to have other places where the log is not written to the database due to some error condition, but no exception is raised. Line 87 has a check for a null or closed connection, and simply returns after logging if the connection is not available.
{code:title=JDBCDatabaseManager.java|borderStyle=solid}
87: if (!this.isConnected() || this.connection == null || this.connection.isClosed()) {
LOGGER.error("Cannot write logging event; manager [{}] not connected to the database.", this.getName());
return;
}
{code}
Unless I am missing something, it appears to me that the JDBCAppender is not written with failover in mind.
> Failover appender doesn't fail over on JDBC appender error
> ----------------------------------------------------------
>
> Key: LOG4J2-291
> URL: https://issues.apache.org/jira/browse/LOG4J2-291
> Project: Log4j 2
> Issue Type: Bug
> Components: Appenders
> Affects Versions: 2.0-beta7
> Environment: Java version 1.6_045 and Oracle 11g 11.2.0.3.0 database on 64-bit machine. It's running within eclipse but I don't think that should make a difference.
> Reporter: Asaf Erlich
> Priority: Minor
>
> When I configure a Failover appender using the jdbc appender as primary and console/file as secondary if I get a database error It prints something to System.err, but not to the file/console as expected.
> How to recreate:
> Make sure a jdbc appender works first.
> Prepare a configuration similar to the one below:
> <?xml version="1.0" encoding="UTF-8"?>
> <configuration status="WARN">
> <appenders>
> <Jdbc name="HubManagerDatabaseLog" tablename="HUB_MANAGER_LOG">
> <ConnectionFactory class="com.somecompany.server.dal.DalCommon" method="getDatabaseInstanceConnection"/>
> <Column name="LOG_DATE" isEventTimestamp="true" />
> <Column name="LOG_THREAD" pattern="%thread" />
> <Column name="LOG_LEVEL" pattern="%level" />
> <Column name="LOG_CLASS" pattern="%logger" />
> <Column name="LOG_METHOD" pattern="%method" />
> <Column name="LOG_MESSAGE" pattern="%message" />
> <Column name="LOG_EXCEPTION" pattern="%exception" />
> </Jdbc>
> <FastRollingFile name="HubManagerFileLog" filename="logs/HubManager.log" filePattern="logs/HubManager-%d{COMPACT}.log">
> <PatternLayout pattern="%d [%thread] %-5level %logger.%method - %message %exception%n" />
> <Policies>
> <SizeBasedTriggeringPolicy size="5MB"/>
> </Policies>
> <!-- <DefaultRolloverStrategy max="50"/> -->
> </FastRollingFile>
> <Console name="Console" target="SYSTEM_OUT">
> <PatternLayout pattern="%d [%thread] %-5level %logger.%method - %message %exception%n" />
> </Console>
> <Failover name="PrimaryDatabaseLoggingIfFailGoToFile" primary="HubManagerDatabaseLog" suppressExceptions="false">
> <Failovers>
> <appender-ref ref="HubManagerFileLog"/>
> </Failovers>
> </Failover>
> </appenders>
>
> <loggers>
> <logger name="com.exzac" level="DEBUG">
> <appender-ref ref="PrimaryDatabaseLoggingIfFailGoToFile"/>
> <appender-ref ref="Console"/>
> </logger>
> <root level="DEBUG">
> </root>
> </loggers>
> </configuration>
> Run the following in a test java class that correctly has the above xml configuration on the build path:
> import org.apache.logging.log4j.LogManager;
> import org.apache.logging.log4j.Logger;
> public class TestFailOverAppender {
> private static final Logger LOGGER = LogManager.getLogger(TestFailOverAppender.class);
> public static void main(final String[] args) {
> final String shortString = "FailOver Short message that should go to database";
> LOGGER.info(shortString);
> final StringBuilder longString = new StringBuilder(shortString);
> while (longString.length() < 4000) {
> longString.append(shortString);
> }
> LOGGER.info(longString.toString());
> LOGGER.info("FailOver short string after message");
> }
> }
> I have tried setting suppressExceptions as false/true. I have tried replacing the fileappender (which works normally) with just console instead and saw the same result. This may or may not be related to another JIRA issue I found, LOG4J2-126.
> If there is simply something wrong with my configuration please let me know. I tried following the documentation as much as possible. Thank you.
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