Common SVN related issues faced with WSO2 products and how they can be solved

Issue 1

TID: [0] [ESB] [2015-07-21 14:49:55,145] ERROR {org.wso2.carbon.deployment.synchronizer.subversion.SVNBasedArtifactRepository} -  Error while attempting to create the directory: http://xx.xx.xx.xx/svn/wso2/-1234 {org.wso2.carbon.deployment.synchronizer.subversion.SVNBasedArtifactRepository}
org.tigris.subversion.svnclientadapter.SVNClientException: org.tigris.subversion.javahl.ClientException: svn: authentication cancelled
    at org.tigris.subversion.svnclientadapter.javahl.AbstractJhlClientAdapter.mkdir(AbstractJhlClientAdapter.java:2524)
    at org.wso2.carbon.deployment.synchronizer.subversion.SVNBasedArtifactRepository.checkRemoteDirectory(SVNBasedArtifactRepository.java:240)


Reason : The user is not authenticated to write to the provided SVN location i.e.:- http://xx.xx.xx.xx/svn/wso2/ . When you see this type of an error, verify the credentials you have given under the svn configuration in the carbon.xml

    <DeploymentSynchronizer>
        <Enabled>true</Enabled>
        <AutoCommit>false</AutoCommit>
        <AutoCheckout>true</AutoCheckout>
        <RepositoryType>svn</RepositoryType>
        <SvnUrl>http://svnrepo.example.com/repos/</SvnUrl>
        <SvnUser>username</SvnUser>
        <SvnPassword>password</SvnPassword>
        <SvnUrlAppendTenantId>true</SvnUrlAppendTenantId>
    </DeploymentSynchronizer>

Issue 2

TID: [0] [ESB] [2015-07-21 14:56:49,089] ERROR {org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask} -  Deployment synchronization commit for tenant -1234 failed {org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask}
java.lang.RuntimeException: org.wso2.carbon.deployment.synchronizer.DeploymentSynchronizerException: A repository synchronizer has not been engaged for the file path: /home/wso2/products/wso2esb-4.9.0/repository/deployment/server/
    at org.wso2.carbon.deployment.synchronizer.internal.DeploymentSynchronizerServiceImpl.commit(DeploymentSynchronizerServiceImpl.java:116)
    at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.deploymentSyncCommit(CarbonDeploymentSchedulerTask.java:207)
    at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.run(CarbonDeploymentSchedulerTask.java:128)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)

Reasons:

Even though you see this exception, the actual cause of the issue could be something else. So note that when you see this exception, you will have to go up the wso2carbon.log and see whether you see any related exceptions near the server startup logs.

(I) SVN version mismatch between local server and the SVN server (Carbon 4.2.0 products support SVN 1.6 only.

Solution - Use the SVN kit jar 1.6 in Carbon server

See https://docs.wso2.com/display/CLUSTER420/SVN-based+Deployment+Synchronizer)

(II) If you have configured your server with a different SVN version than what's in the SVN server and even if you use the correct svnkit jar at the Carbon server side later, the issue will not get resolved

Solution - Remove all the .svn files under $CARBON_HOME/repository/deployment/server folder

(III) A similar issue can be observed when the SVN server is not reachable.

Issue 3

 

[2015-08-28 11:22:27,406] ERROR {org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask} - Deployment synchronization update for tenant -1234 failed java.lang.RuntimeException: org.wso2.carbon.deployment.synchronizer.DeploymentSynchronizerException: No Repository found for type svn at org.wso2.carbon.deployment.synchronizer.internal.DeploymentSynchronizerServiceImpl.update(DeploymentSynchronizerServiceImpl.java:98) at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.deploymentSyncUpdate(CarbonDeploymentSchedulerTask.java:179) at org.wso2.carbon.core.deployment.CarbonDeploymentSchedulerTask.run(CarbonDeploymentSchedulerTask.java:137) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: org.wso2.carbon.deployment.synchronizer.DeploymentSynchronizerException: No Repository found for type svn at org.wso2.carbon.deployment.synchronizer.repository.CarbonRepositoryUtils.getDeploymentSyncConfigurationFromConf(CarbonRepositoryUtils.java:167) at org.wso2.carbon.deployment.synchronizer.repository.CarbonRepositoryUtils.getActiveSynchronizerConfiguration(CarbonRepositoryUtils.java:97) at org.wso2.carbon.deployment.synchronizer.internal.DeploymentSynchronizerServiceImpl.update(DeploymentSynchronizerServiceImpl.java:66) ... 9 more 

Reason:

You will notice this issue when the svn kit (i.e. for latest versions of Carbon i.e. 4.4.x the jar version would be svnkit-all-1.8.7.wso2v1.jar) jar is not available in $CARBON_HOME/repository/components/dropins folder

Sometimes dropping the svn-kit-all-1.8.7.wso2v1.jar would not solve the problem. In such situations, verify whether the trilead-ssh2-1.0.0-build215.jar is also available under $CARBON_HOME/repository/components/lib folder.

Solving the famous "java.sql.SQLException: Total number of available connections are less than the total number of closed connections" issue

While starting up your WSO2 product after configuring a registry mount, you may have come across the below issue.

Caused by: java.sql.SQLException: Total number of available connections are less than the total number of closed connections
    at org.wso2.carbon.registry.core.jdbc.dataaccess.JDBCDatabaseTransaction$ManagedRegistryConnection.close(JDBCDatabaseTransaction.java:1349)
    at org.wso2.carbon.registry.core.jdbc.dataaccess.JDBCTransactionManager.endTransaction(JDBCTransactionManager.java:178)
    ... 46 more


When you see the above exception, the first thing you have to do is verify the mount configuration of the registry.xml.

See below. In this config, if you accidentally refer to the dbConfig name of the local DB in the mount, you will get the exception mentioned in the $subject.The correct dbConfig name you should refer to is, wso2Mount where wso2Mount is pointed to an external DB.

E.g. :-

     <currentDBConfig>wso2registry</currentDBConfig>
    <readOnly>false</readOnly>
    <enableCache>true</enableCache>
    <registryRoot>/</registryRoot>

    <dbConfig name="wso2registry">
        <dataSource>jdbc/WSO2CarbonDB</dataSource>
    </dbConfig>

    <dbConfig name="wso2Mount">
        <dataSource>jdbc/WSO2RegDB</dataSource>
    </dbConfig>

    <remoteInstance url="https://localhost:9443/registry">
        <id>instanceid</id>
        <dbConfig>wso2Mount</dbConfig>
        <readOnly>false</readOnly>
        <enableCache>true</enableCache>
        <registryRoot>/</registryRoot>
    </remoteInstance>

    <mount path="/_system/config" overwrite="true">
        <instanceId>instanceid</instanceId>
        <targetPath>/_system/nodes</targetPath>
    </mount>

Dealing with "HTTP 502 Bad Gateway"

Recently, while configuring WSO2 products with NginX, we were struggling to connect to the management console of the product since it was returning "HTTP 502 Bad Gateway" error. After doing some research, found out that it was a problem with SELinux.

There are two SELinux boolean settings available by default. One of them is httpd_can_network_connect which allows httpd to connect to anything on the network.

So to enable this, I executed the below command and everything worked well.

sudo setsebool -P httpd_can_network_connect 1
However, there are other similar variables that can be enabled other than this and they are explained in detail in [1].

[1] - https://www.axivo.com/resources/selinux-booleans-explained.22/

How to print the results summary when JMeter is running on headless mode

When you are running JMeter in GUI mode, you can easily view the results through the Summary report or through the Aggregate report.

But how do you view the summary if you are running JMeter in headless mode?

This can be configured through the jmeter.properties file which resides in $JMETER_HOME/bin folder.

Note that this is enabled by default in latest versions of JMeter. E.g.:- Version 2.13

#--------------------------------------------------------------------------- # Summariser - Generate Summary Results - configuration (mainly applies to non-GUI mode) #--------------------------------------------------------------------------- #

# Define the following property to automatically start a summariser with that name
# (applies to non-GUI mode only)
summariser.name=summary
#
# interval between summaries (in seconds) default 3 minutes
summariser.interval=180
#
# Write messages to log file
summariser.log=true
#
# Write messages to System.out
summariser.out=true