The events logger stores event data in event data files.
The EGO allocation event data file is named ego.stream by default and has a default maximum size of 10MB.
When a data file exceeds this size, the events logger archives the file and creates a new data file. The events logger maintains one archive file and overwrites the old archive with the new archive. The event data loaders read both the data files and the archive files.
The default archive file name is ego.stream.0 for EGO, and the data and archive files are both located in EGO_TOP/kernel/work/data by default.
If your system logs a large number of events, you should increase the maximum file size to see more archived event data. If your disk space is insufficient for storing these files, you should decrease the maximum file size, or change the file path to a location with sufficient storage space.
You can manage your event data files by editing the relevant system configuration files. Edit ego.conf for the EGO allocation event data file configuration.
Tuning may help to prevent event data files from switching too quickly to be read by the data loader, resulting in lost records in the data being loaded.
The following factors should be considered when tuning the event data loader:
This is the most critical factor. For a production cluster, check the stream file switch time. The average switch time should be greater than 3 minutes. If the switch time is too frequent, increase the file size. Note that the file size also impacts the stream file writing speed so if the file is too large, writing speed will slow down.
The stream file size, specified in Mbytes, is controlled by the parameter EGO_DATA_MAXSIZE in ego.conf.
This value, specified in seconds, must be less than the stream file switch time but greater than the database loading speed.
To set the loader interval, open the plc_ego.xml file and change the Interval attribute for egoeventsloader. For example:
The remaining factors are related to data loading performance and should all be optimized for speed.
If tuning cannot provide satisfactory loader performance, it is possible to create multiple plc service instances for balancing the workload. Contact Platform Professional Services for more information.