FAQ
MyST Management
MyST performance management?

Consider the following options for performance and capacity management of Myst.

Linux Entropy (random/urandom)

The OS may be running out of entropy. See the Oracle Support article below for more information. Changing from /dev/random to /dev/./urandom not only significantly improves OFMW but will improve Myst SSH connectivity time as Myst also relies on Java.

How to Diagnose a Linux Entropy Issue on WebLogic Server Instances

Platform Instance Action Checker

Myst Studio creates a background thread for every platform instance. When each thread executes it consumes seconds of CPU time to check for new actions against its platform instance.

As the the number of platform instances increase the threads will begin to overlap each other resulting in constant high CPU usage.

Use the fc.quiet_period_sec.platform_instance to reduce the platform instances' background check intervals. The default is 15 seconds.

The value can be roughly formulated to <number_of_platform_instances> X 2. For example, for 60 platform instances try experimenting with 120 (seconds).

Edit the fc-configuration.properties.

docker exec -ti myststudio_web bash
vi /usr/local/tomcat/conf/fusioncloud/fc-configuration.properties

Update as required.

fc.host.address=XXXXXXXXX
fc.quiet_period_sec.platform_instance=120
fc.port=XXXX

Restart the container.
```
docker restart myststudio_web
```

Tuning Memory parameters

Memory parameters can also be tuned to improve the performance. In order to tune the memory, you can apply the following parameters in the docker-compose.yml file and restarting Myst for the values to take effect.

    environment:
      CATALINA_OPTS: "-Xmx3072m -Xms3072m"

Improving Log Rotation to Reduce Disk Usage

Add log rotation in the docker-compose.yml file to reduce disk usage. This can be added to any of the services inside the file.

Edit the docker-compose.yml

cd /opt/myst-studio/conf
vi docker-compose.yml

Set the values suitable as per your environment.

 logging:
   options:
     max-size: "10M"
     max-file: "5"

Restart Myst which will recreate the web container with the new changes
```
cd  /opt/myst-studio/bin
./restart.sh
```

Packet Size Breach / Support Artifact failure

Diagnosis

Running a Myst action returns an error in the log.

019-04-15 12:52:50,555 [d9-faa98740671a] ERROR c.r.f.p.c.p.s.InvokeMyST       - Error
java.lang.Exception: Error occurred in the remote agent
2019-04-15 12:52:50,885 [d9-faa98740671a] ERROR o.h.e.j.s.SqlExceptionHelper   -Packet for query is too large (25134636 > 4194304). You can change this value on the server by setting the max_allowed_packet' variable.

Cause

A support zip can be supplied to the Myst support team to help diagnose issues. The zip is generated when a Myst Studio action fails.

Sometimes the zip fails to upload to the Myst Studio database due to packet size restrictions. This happens when the zip is larger than the default 2mb possibly due to artifacts being in the zip as well.

Resolution

Packet size max_allowed_packet_size can be altered in the 'db' docker service to increase the size. This is defined docker-compose.yml. NOTE: Be cautious of setting this size too large as it will affect the java heap space usage.

Backup your Myst Studio database

cd  /opt/myst-studio/bin
./backup-database.sh

Add the line below to increase the max_allowed_packet to 32M to the db docker-compose.yml
Restart Myst which will recreate the db container with the new max_allowed_packet changes
```
cd  /opt/myst-studio/bin
./restart.sh
```

NOTE: The value/size of the max_allowed_packet can be set (to any value), based on one's requirement

Raise a Myst Support Ticket

Feel free to raise a support ticket if there are other suggestions you would like to make or requests you would like make.

MyST performance management?