Installation on some Linux distributions can be troublesome, here are a few things to ensure when running on linux.

Unable to create native thread

You might get an error like this: java.lang.OutOfMemoryError: unable to create native thread: possibly out of memory or process/resource limits reached in the logs - this is not an indication that Ceptor has run out of memory (despite the name of the exception) but rather that a new thread cannot be created because a limit of processes, tasks or maximum file handles has been reached.

See below for information on how to fix these kind of problems:

Setting ulimit flags correctly

Default limits for maximum file handles are often too low for most services on some linux distribution.

You can view current limits by running ulimit -a to display current settings.

These limits can be changed by running ulimit -n to change max number of file handles (open files, sockets etc.) and ulimit -u to change the limits for processes/threads.

You can also edit the file /etc/security/limits.conf and change the settings permanently there - refer to the documentation for your particular linux distribution for details.

Below is an example of setting the values for all users (replace * with specific username that you use to launch Ceptor)

*     soft  nproc 8192
*     hard  nproc 8192
*     soft  nofile 30000
*     hard  nofile 30000

In this example the maximum number of processes/threads is set to 8192 and max number of filehandles to 30000 - your needs will vary so change them according to load.

Pay special attention to number of concurrently open socket connections to clients - on very heavily loaded systems you might need the number of filehandles increased beyond these example values.

When installing from RPM or DEB images

When installing from RPM or DEB images, a service (pplauncher_service) is automatically created and set to start as a systemd service

This service is limited by systemd settings that can affect it - e.g. the DefaultMaxTasks=512 will cause it to fail since no more than 512 threads can be started across all processes within the same service.

One way to fix this, is to edit /etc/systemd/system.conf and set DefaultTasksMax=4096 - another is to edit the service file for the pplauncher directly /etc/systemd/system/pplauncher_service.service and set TasksMax=4096 within it in the [Service] section.

Ceptor versions newer than 6.5.3 will set this value by default.