Incorrect number of Java Processes in Solr

  • Updated

Below is a tool for diagnosing a lack of or extra Java processes on the Solr server. Whenever diagnosing a Solr-based issue, it is recommended to check the number of Java processes.

Process Explorer is a helpful tool for diagnosing what is happening with the Java.exe processes of Solr. Below is a download link for the tool:
https://technet.microsoft.com/en-us/sysinternals/processexplorer.aspx

  1. Run the Process Explorer app on the Solr server.
  2. Scroll down until you see Java.exe.
  3. Hover over the java.exe. You see a block of text like below. This is normal.

TomcatManifoldRunHSQL

By default, 9.1 Solr has three java processes; 9.2 Solr has four. If you see extra java processes, that typically means that the Java.exe processes did not shut down fully prior to a start-up attempt. Follow these steps to rectify that issue.

  1. View the processes in Process Explorer.
  2. Look for a process called (viewed at the end of the Command Line and just before the Path): Manifoldcf.agents.AgentStop and manifoldcf.agents.initializeandrestart
  3. End the Manifoldcf.agents.AgentStop process and then the manifoldcf.agents.initializeandrestart process.
  4. The correct manifoldcf.agents.AgentRun process appears.

This can be helpful in ending infinite Solr crawls, if the Solr Process Manager Service has been restarted several times.