[DERBY-6554] Too much contention followed by assert failure when accessing sequence in transaction that created it

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.9.1.0, 10.10.2.0, 10.11.1.1
• Fix Version/s: 10.11.1.1
• Component/s: SQL
• Labels: derby_backport_reject_10_10
• Urgency: Blocker
• Issue & fix info: Repro attached
• Assignee: Unassigned
• Reporter: Knut Anders Hatlen
• Created: 25/Apr/14 11:53
• Updated: 09/Sep/16 09:51
• Resolved: 19/May/14 17:32

Description

ij version 10.11
ij> connect 'jdbc:derby:memory:db;create=true' as c1;
ij> autocommit off;
ij> create sequence seq;
0 rows inserted/updated/deleted
ij> values next value for seq;
1          
-----------
ERROR X0Y84: Too much contention on sequence SEQ. This is probably caused by an uncommitted scan of the SYS.SYSSEQUENCES catalog. Do not query this catalog directly. Instead, use the SYSCS_UTIL.SYSCS_PEEK_AT_SEQUENCE function to view the current value of a query generator.
ij> rollback;
ERROR 08003: No current connection.
ij> connect 'jdbc:derby:memory:db' as c2;
ij(C2)> autocommit off;
ij(C2)> create sequence seq;
0 rows inserted/updated/deleted
ij(C2)> values next value for seq;
1          
-----------
ERROR 38000: The exception 'org.apache.derby.shared.common.sanity.AssertFailure: ASSERT FAILED Identity being changed on a live cacheable. Old uuidString = 0ddd00a9-0145-98ba-79df-000007d88b08' was thrown while evaluating an expression.
ERROR XJ001: Java exception: 'ASSERT FAILED Identity being changed on a live cacheable. Old uuidString = 0ddd00a9-0145-98ba-79df-000007d88b08: org.apache.derby.shared.common.sanity.AssertFailure'.

Issue Links

• blocks: DERBY-6542 Improve the concurrency of identity columns by using SYS.SYSSEQUENCES
• is related to: DERBY-6692 Self-deadlock when inserting row with identity column in soft-upgraded database
• is related to: DERBY-6572 Raise SelfDeadlock exception when a nested sub transaction has to wait for a lock held by its parent transaction.
• is related to: DERBY-6573 Don't throw an exception if a nested sub transaction can't immediately get a blocking lock held by its parent transaction.