SR-D68707 · Issue 529871
Update Handler will not run during migration
Resolved in Pega Version 8.4.1
Rolling restart of DataFlow, ADM ,VBD, and Util Tiers failed with a PENDING_JOINING error after an in-place upgrade. This was traced to the logic for the update timing: when nodes start after an upgrade from 7.x to 8.x they will migrate data flow runs. Migration happens on only one node, and while it's in progress the other nodes will wait until migration finishes before they come up. At this point the state of the data flow services will be 'PENDING JOINING'. The issue is that while migrating runs, the Data Flow Update Handler was triggered to validate whether there were nodes available on the service the run belongs to. This call can cause the corresponding data flow service to be initialized, but the call will be blocked since all services wait for the migration to end. This resulted in a deadlock which prevented all nodes from coming up successfully. To resolve this, the process has been updated to skip the update handler during migration to avoid triggering the initialization of client services that are waiting on the migration lock.
SR-D74117 · Issue 539463
DDS service will not run Hazelcast check if external Cassandra is configured
Resolved in Pega Version 8.4.1
Services were not responding, and thread dumps seen in the logs indicated that a large number of threads were waiting for one to come back from getting the cluster state for a DSM process. Investigation showed that the threads were waiting for a Hazelcast response about the cluster state. However, since a Hazelcast call is not needed when Pega is configured with external Cassandra, the DDS Service code has been changed to not to check for candidate nodes if configured with external Cassandra cluster.
SR-D75519 · Issue 536719
Corrected calculating propensities
Resolved in Pega Version 8.4.1
Several PMML models designed to compare the outcomes to a control dataset experienced an issue where the probability scores in Pega did not match the original control dataset. The PMML model was also tested using KNIME; those results matched Pega but not the original control dataset. Investigation showed that the JPMML evaluator contained outdated code, and the incorrect calculations have been resolved.
SR-D77157 · Issue 544473
DataSet preview will use date instead of datetime
Resolved in Pega Version 8.4.1
While using a DataSet preview functionality, the date appeared as reduced by one day. This has been resolved by parsing date as 'date' instead of 'datetime' to avoid issues with timezone interactions.
SR-D78940 · Issue 542928
Dataflow monitoring enhanced
Resolved in Pega Version 8.4.1
Enhanced monitoring and healthchecks have been added for dataflow and alerts.
SR-D79145 · Issue 543055
Added tokenizer for KeyWord-Based Topic Detection phrases
Resolved in Pega Version 8.4.1
KeyWord-Based Topic Detection was not Working for "Enrollment/Re-Enrollment" as a word, for example a categorization model with the text 'This is an email related to Enrollment/Re-Enrollment'. To facilitate this use, a tokenizer has been added to break 'should',' must', and 'and' words into components for a taxonomy match.
SR-D82150 · Issue 546532
Properties persist after revision import
Resolved in Pega Version 8.4.1
"When properties were added to a form, they sometimes disappeared after revision import even though the properties always remained visible in a strategy. Investigation showed that the Form changes made in a DD rule were not properly updated in the pyEditElement section. To correct this, logic has been added to handle the form changes in the DD in the following activities:Data-Rule-Summary.pyMergePropositions Data-Rule-Summary.pyRemoveDDRules Data-Rule-Summary.pyWithdrawDDChanges Data-Rule-Summary.pyRemoveRestoreDDRule"
SR-D82727 · Issue 547725
Improved management for table pr_log_dataflow_events
Resolved in Pega Version 8.4.1
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 546342
Updated COUNT logic for strategies with ssavm set to true
Resolved in Pega Version 8.4.1
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.
SR-D85558 · Issue 548287
Handling added for prolonged Heartbeat Update Queries
Resolved in Pega Version 8.4.1
After restart, the pyFTSIncrementalIndexer queue size had hundreds of thousands of entries even though it was empty prior to the restart.Investigation traced this to a job scheduler that checked all the database connections everyday at 1 EST by using a list that contained some connections which did not exist. Checking those invalid connections caused other update queries to queue and wait, resulting in the update heartbeat query taking longer than its default beat. This caused a Split Brain issue wherein other nodes considered the long-executing node to be dead and triggered a rebalance while the node itself continued to execute partitions thinking that it was healthy. This caused duplicate processing of records. To resolve this, a fail safe has been added: while updating heartbeat in Service Registry, nodes will enter safe mode when the update query is taking longer than the default beat.