[YSQL] Ignore txn priority bound GUCs in read committed isolation #19921
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area/ysql
Yugabyte SQL (YSQL)
kind/bug
This issue is a bug
priority/medium
Medium priority issue
status/awaiting-triage
Issue awaiting triage
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pkj415
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Dec 5, 2023
…tion Summary: `yb_transaction_priority_lower_bound` and `yb_transaction_priority_upper_bound` don't make sense for read committed isolation since it provides wait-on-conflict semantics even if enable_wait_queues is set to false by always using the kHighestPriority for all RC transactions (see 9f2cc7f for reasoning, specifically point (2) in its commit summary). This diff ensures that these GUCs are ignored in RC isolation. Without this diff, the following bug can be seen: ``` Start a cluster with just the tserver gflag yb_enable_read_committed_isolation=true create table demo (id bigint primary key, value int); insert into demo values (123, 103); session 1: set yb_transaction_priority_lower_bound to 0.1; session 1: set yb_transaction_priority_upper_bound to 0.4; session 2: set yb_transaction_priority_lower_bound to 0.6; session 2: set yb_transaction_priority_upper_bound to 0.9; session 1: begin transaction isolation level read committed; session 2: begin transaction isolation level read committed; session 1: update demo set value=1 where id=123; <succeeds...> session 2: update demo set value=2 where id=123; <this succeeds as well instead of waiting!> session 1: commit; ERROR: Transaction ********-****-4***-****-************ expired or aborted by a conflict: 40001 ``` Jira: DB-8864 Test Plan: ./yb_build.sh release --java-test org.yb.pgsql.TestPgWithoutWaitQueuesIsolationRegress Added yb_read_committed_insert_duplicate_key_error to yb_pg_isolation_schedule Reviewers: tvesely, bkolagani, rsami Reviewed By: tvesely, bkolagani Subscribers: yql Differential Revision: https://phorge.dev.yugabyte.com/D30114
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Jira Link: DB-8864
Description
yb_transaction_priority_lower_boundandyb_transaction_priority_upper_bounddon't make sense for read committed isolation since it provides wait-on-conflict semantics even ifenable_wait_queuesis set to false.Ensure that these are ignored in RC isolation.
Issue Type
kind/bug
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