INC-142216 · Issue 596668
VBD performance improvements
Resolved in Pega Version 8.5.2
Performance issues were seen when running a decision funnel simulation. As part of the simulation, a VBD collection was created on the fly to store the metrics and linked to the simulation. Before each insert, which happened in batches of 500 records, there was a check if such collection exists. This check was required in earlier versions as the process relied on the VBD service being running, and the run would fail otherwise. Recently, VBD handling became more resilient and was updated to allow inserts even if the VBD server is down. If the VBD service is stopped before the simulation is completed, the simulation will continue writing records. When the VBD service starts again, it reads the backlog, and the simulation displays the final results. To adapt to this resiliency and improve performance, the system has been updated so that the VBD collection is not created and checked before the insert call, but only when the simulation is run or scheduled.
INC-143441 · Issue 608899
Strategy Simulation Runs made more resilient
Resolved in Pega Version 8.5.2
Intermittently, a decision funnel simulation would fail with particular strategy logic or a particular StrategyTracker would not contain the results for all components so the system would not be able to calculate input SRs. Handling has now been added to make the simulations more resilient so they will not fail with a null pointer error due to incomplete strategy inputs.
INC-144864 · Issue 599146
Unneeded AUC error percentage calculation removed for better system performance
Resolved in Pega Version 8.5.2
When generating snapshots of the ADM models, an inefficiency in the metric calculation for the AUC error percentage caused an excessive amount of memory to be allocated which could cause slowdown or require a system reboot. This has been resolved by removing the problematic AUC error percentage calculation as it is not used in the UI.
INC-148006 · Issue 605581
Enhancements added for very heavy use of strategy decision logic
Resolved in Pega Version 8.5.2
Recent updates were made to improve memory performance for scenarios where a single request primary page had tens of thousands of pages under an embedded pagelist property and the decision logic involved a strategy running on all the pages in that page list. To further improve performance, the array iterator has been modified and a DSS has been added that makes the threshold (50) in SSAExecutionContextIteratorFactory tunable.
INC-150854 · Issue 608368
Logic optimization disabled in offers
Resolved in Pega Version 8.5.2
Offers that should not be eligible to customers were passing through even though the offer was narrowed down to using “OR” conditions in the Engagement policies. This was traced to the logic optimization ignoring precedence, and has been resolved by disabling the optimization.
INC-126796 · Issue 561533
Modifications to getFunctionalServiceNodes process
Resolved in Pega Version 8.2.7
The count of the Interaction History write related threads was increasing rapidly and a stack trace indicated "waiting on condition" and "java.lang.Thread.State: WAITING (parking)" errors. Investigation showed that this was due to getFunctionalServiceNodes using Hazelcast to determine node status by making a service request on an installation with a very large number of nodes, causing thread locking. To resolve this, the implementation has been updated to avoid calling getFunctionalServiceNodes on save of Interaction History, instead using Cassandra and only calling getFunctionalServiceNodes on the master node, not on all nodes.
INC-128385 · Issue 564519
Behavior made consistent between SSA and legacy engines
Resolved in Pega Version 8.2.7
There was a behavioral disparity between the legacy execution engine and the SSA engine where the latter was not creating a new page when the index was one above the size of the page list. This has now been corrected in order to make the SSA behavior fully backward compatible with the legacy engine, i.e. a new blank page will be added to the list if the index is one above the size of the list.
INC-128898 · Issue 564690
Updated precondition checks for Tumbling Time data in event strategies
Resolved in Pega Version 8.2.7
Tumbling Time data keys in event strategies were not being properly executed when certain window configurations were used. This was has been resolved by turning off the optimalization of Cassandra reads for small windows when window size is not known upfront and set dynamically (set size by property). In addition, an issue with Cassandra timeouts after the dataflow run had been running for several months has been resolved by adding a 'time to live' value for tumbling time windows, and event strategies has been switched to use leveled compaction by default.
SR-D82727 · Issue 547723
Improved management for table pr_log_dataflow_events
Resolved in Pega Version 8.2.7
The Lifecycle event table was sometimes growing too large. This additional strain of database transaction volume caused poor performance on the Dataflow tier and lead to cluster instability and time-consuming cluster restarts. Due to problems in one of the Pulse tasks, the Pulse thread was not processing single case metrics properly and causing the unbounded queue for single case to grow. This has been addressed by switching to a fixed queue size, which is configurable with the DSS: dnode/single_case_queue_size. The default value of the DSS is 4000, and if changed a system restart is required. An error will be logged each 1000 queue misses, and metrics will be dropped if the queue is full. In addition, the Pulse task frequency has been improved and managed to prevent interference with other Pulse tasks and will be triggered only if a run is system-paused for a long interval. Rebalances now have a failsafe if something unexpected happens during the Pausing of the run, and If the cluster becomes unstable, the life cycle events logs may be disabled with dataflow/run/events/persist .
SR-D85095 · Issue 546339
Updated COUNT logic for strategies with ssavm set to true
Resolved in Pega Version 8.2.7
An error was seen when attempting to save a strategy after setting ssavm to true, indicating an issue in the “COUNT” method in Group By shape. Since the source field is not used and does not need to be evaluated here, the system has been updated to ignore the source field if the operation is COUNT.