INC-161604 · Issue 631764
Corrected unreleased database connections
Resolved in Pega Version 8.6
When using a custom activity that calls Dataset-execute on a database table dataset, the DSS Pega-Engine.prconfig/classmap/usemergestatement/default was set to false and the prepared statement for database table dataset was failing. Upon the failure, an exception was generated that prevented the database connection from being released. This has been corrected.
INC-161604 · Issue 631762
Node stability improved when adding relevant records
Resolved in Pega Version 8.6
A node was going down after maxing out the database connection pool whenever the inbound service call was invoked. This was traced to several relevant record-related database queries being invoked within a short time for marking 'when' rules referenced in the proposition filter rule as relevant records. This has been resolved by adding 'when' rules as Relevant Records based on a DSS and not adding auto-generated 'when' rules at all.
INC-163723 · Issue 633441
Queue Processors made more robust
Resolved in Pega Version 8.6
After upgrade, multiple queue processors were not running as expected. Attempting to restart them generated an error. Investigation showed that the real time data flow runs were not picking up or accepting assignments because the local node was under the impression it was still processing data. In this case, the need to synchronize the state of multiple threads caused the queue processors to become stuck in an initializing state due to a race condition that caused the data flow engine to think this run still had threads running when all threads were already stopped. To resolve this, the callback handling has been simplified and made more robust. In addition, in some cases the data flow leader node would believe the service nodes did not accept assignments even when they did. This occurred if many runs and nodes were involved, and was traced to an implicit limit on the NativeSQL query used to read the data to see which assignments were accepted. To resolve this, the key-value store in the Service Registry has been modified to allow a query of more than 500 entries at once.
INC-164581 · Issue 634154
Import UI option updated to handle data import for upgrades
Resolved in Pega Version 8.6
After upgrade from Pega 8.1 to 8.5, importing data into the datasets using the Actions->Import UI option was not working. This was due to the previous save operation used in import being deprecated, and has been resolved by instituting a new save operation in import to handle this scenario.
INC-166354 · Issue 637300
Queue Processors made more robust
Resolved in Pega Version 8.6
After upgrade, multiple queue processors were not running as expected. Attempting to restart them generated an error. Investigation showed that the real time data flow runs were not picking up or accepting assignments because the local node was under the impression it was still processing data. In this case, the need to synchronize the state of multiple threads caused the queue processors to become stuck in an initializing state due to a race condition that caused the data flow engine to think this run still had threads running when all threads were already stopped. To resolve this, the callback handling has been simplified and made more robust. In addition, in some cases the data flow leader node would believe the service nodes did not accept assignments even when they did. This occurred if many runs and nodes were involved, and was traced to an implicit limit on the NativeSQL query used to read the data to see which assignments were accepted. To resolve this, the key-value store in the Service Registry has been modified to allow a query of more than 500 entries at once.
SR-69015 · Issue 619995
Unescaping characters implemented for expressions
Resolved in Pega Version 8.3.6, Resolved in Pega Version 8.4.4, Resolved in Pega Version 8.5.3, Resolved in Pega Version 8.6
An issue where expression builder statements were evaluated differently at runtime than at testing has been resolved. Pega Platform expressions with String literals(that is, sequences of characters enclosed in quotation marks) now unescape characters in strategy shapes such as Set Property or Filter.
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 .