Frequently Asked Questions¶

Here, you find answers to the frequently asked questions.

How Do I Check the Version on Linux?¶

On Linux, PLOSSYS Output Engine is installed using rpm packages. For more information about the installation, refer to Installation.

This is how you get the version of the installed

PLOSSYS Output Engine bundle:
```
rpm -qa | grep plossys
```
the single rpm packages:
```
rpm -qa | grep seal
```

What Happens If A Output Engine Server Crashes or Is Stopped?¶

Unless the server is the primary MongoDB server, nothing will happen. The jobs arrive and will be processed without any problems.

If the primary MongoDB server is stopped or crashes, no jobs are written into MongoDB as long as the remaining MongoDB servers have elected the new primary server. Normally, this only takes some seconds. The checkin services use a buffer when connecting to the MongoDB and normally this is enough so that no jobs will be lost.

If two of the three servers crash or are stopped, the election no longer works due to the election requires a mayority. As soon as one of the two servers is working again, an election takes place and PLOSSYS Output Engine can proceed working.