INC-126129 · Issue 569666
PropertyToColumnMap made more robust
Resolved in Pega Version 8.1.9
The DF_ProcessEmails dataflow was intermittently failing with a StageException error. This was traced to schema changes being propagated asynchronously by system pulse, which seem to have caused PropertyToColumnMap to cache stale schema. To resolve this, if the property mapping is not found the first time, the system will make a second attempt to get the mapping. Additional logging has also been added for better diagnostics.
INC-128385 · Issue 564521
Behavior made consistent between SSA and legacy engines
Resolved in Pega Version 8.1.9
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-129222 · Issue 568530
Handling improvements for commit logs
Resolved in Pega Version 8.1.9
The ADM commit log logs the number of unconsumed messages that are going to expire. In certain circumstances, it can include unconsumed messages that are not going to expire in the count. Because they are not expired and removed, the environment was running out of disk space due to the ADM commitlogs table growing larger than expected and performance issues were seen. To resolve this, a new adm_commitlog.adm_responses_commit_log_date_tiered table has been created, with a default_time_to_live of 24 hours. DateTieredCompactionStrategy has been set with max_window_size_seconds as 24hrs and tombstone_compaction_interval as 24hrs.
INC-132976 · Issue 580685
Performance improvements for Test Strategy data flow
Resolved in Pega Version 8.1.9
In the Test Strategy panel under Single case -> "Settings", selecting the "Data flow" option and choosing CustomerData dataflow was taking an excessive amount of time to run on a system with an extremely large database. To improve performance, two areas have been addressed: 1) the default behavior for record key suggestions in the test panel has been modified to collect only the ID as the additional data is not necessary at that time; 2) a DSS has been added that will opt out of reading and collecting the customer IDs in order to minimize data stored on the clipboard.
INC-138037 · Issue 586593
Strategy handling updated for very large systems using IH summary
Resolved in Pega Version 8.1.9
When a Strategy in a Real-time dataflow used IH Summary on a system with more than 5000 groups for one eventKey, the message "Error retrieving aggregates from Cassandra KVS" intermittently appeared. Investigation showed that if the number of result rows was greater than the FETCH_SIZE (set to 5000), it meant another read to Cassandra was required and an exception was generated. To resolve this, updates have been made so that instead of returning maps, the system will return iterators and change them to map on the calling thread.
SR-D92734 · Issue 553412
Simulation can take Data flow type as destination
Resolved in Pega Version 8.1.9
Support has been added for Data flow functionality as simulation target and data transform in simulation input.
SR-D90367 · Issue 556687
Cleanup enhanced for long pyEditElement names
Resolved in Pega Version 8.5
A pyEditElement error relating to decision data was seen multiple times in a stack trace. Research showed that while the utility worked as expected for decision data rules with names of less than 30 characters, the pyEditElement section was truncated the name for the decision data. This meant that decision data with the name SampleIssueandSampleGroupTwosalkdjkightntbmkblffvfvfv would be saved as SampleIssueandSampleGroupT for the pyEditElement section. Because of this, the utility failed the match and did not clean up the pyEditElement section. To resolve this, the cleanup utility has been updated to handle pyEditElement sections of decision data with longer names. Additional logging has also been added to improve debugging.
SR-D71621 · Issue 533296
Real time processing picks up correct datetime for Capture Response records
Resolved in Pega Version 8.5
A Realtime Data flow for the Capture Response flow was configured with a strategy shape set to load previous decisions within the past 7 days. Once this Realtime DF was started, attempting to Capture Response for decisions made after that startup timepoint did not work. This was traced to the InteractionID being written with global properties for the datetimes, and has been resolved by making those datetime properties local so the start and end time are not cached and the time range is calculated based on "now”.
SR-D85558 · Issue 548286
Handling added for prolonged Heartbeat Update Queries
Resolved in Pega Version 8.5
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.
SR-D66397 · Issue 530333
ADM out-of-sync corrected for multi-datacenter Cassandra cluster
Resolved in Pega Version 8.5
After setting up the multi-datacenter configuration for a Cassandra cluster that consisted of six nodes in datacenter 1 and three nodes in datacenter 2, failover testing revealed a mismatch in the number of ADM models stored in each datacenter. The mismatch was observed mostly in the number of records present in the "adm_scoringmodel" and "adm_response_commit_log_date_tiered" tables. When Cassandra nodes are down, the other nodes in the cluster will store hints (records to be written) for the down nodes. When these nodes come back online the hints are replayed to those nodes and the data is written. Hints are written for 3 hours, so if a node come back up within 3 hours data is recovered and repairs are not required. The gc_grace_seconds for the above tables that were getting out of sync across the two datacenters was set to zero seconds. The "gc_grace_seconds" attribute is not just used as the time for removal of tombstones, it's also used to set the TTL for records written to the system.hints table. That meant that when the hints were written for the ADM tables for the nodes that were down, they were immediately expired since it was set to 0 and not played back when the terminated nodes restarted and joined the cluster. This has been resolved with this fix for all customers new to this release. Existing customers already on v7.3 or higher will need to complete the local change detailed below: Connect to the Cassandra cluster using cqlsh in the Pega Cassandra distribution and then run ALTER TABLE adm_commitlog.adm_response_commit_log_date_tiered WITH gc_grace_seconds = 86400; to change the relevant setting from zero to the equivalent of one day - the same length of time that the data in the table lives for. This will mean that any hints written can still be used to replay data to another node while the data itself is alive. It does also mean, however, that, given a constant load, a day's worth of expired ADM event data in the table will always be present on the disk, as the tombstones can now not be cleaned up for a day.