SIMCA-online® 17 server memory usage increases over time
Symptoms
Memory usage of the SIMCA-online® server service increases unexpectedly over time under certain circumstances, faster than 16.1 and earlier versions. Under these circumstances, on servers with many project configurations, memory may run out.
This affects SIMCA-online 17.0, 17.0.1 and 17.0.2.
Status
A fix will be made available in SIMCA-online 17.0.3.
Internal bug number: 45532
Cause
By design, internal caches introduced in SIMCA-online 17 are pruned when a model is executed (prediction condition is true or phase execution condition is true). When a model is not executing for a project configuration with execution turned on internal caches are not pruned, resulting in more and more memory being used.
Workaround
Stop execution for projects that are not used for active monitoring to mitigate the problem. This can reduce the number of caches in use and thus the rate of memory growth.
Stop and restart the server service to release all memory. When the server is restarted execution will continue (all data is preserved on disk and resumed), and all caches are emptied.
More information
The issue can be more apparent on servers which have:
- many project configurations with execution turned on
- complex project configurations with many unit groups, units and phases
- long batches with many observations
- a short execution interval, and also many different intervals between configurations
- phase models that are waiting to execute or has finished executing for a batch
- continuous project configurations when the prediction condition is false
