[IGNITE-7575] Concurrent updates of common keys cause silent wrong update count (intermittent issue)

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: sql
• Labels: sql-stability
• Assignee: Unassigned
• Reporter: Pavel Kuznetsov
• Created: 30/Jan/18 19:40
• Updated: 29/Aug/18 08:03

Description

In case of concurrent updates that affects some common keys we get silent wrong update count

There's single table with two columns: key and val.
I'm performing the same query that updates the same 1000 rows using 4 threads. Query doesn't update keys, it only increments val.
In some cases I get expected exception "Failed to update some keys because they had been modified concurrently" or have 1000 updated rows

In the other case, API tells me that more than 1000 rows updated. Expected result are exception or successfull update of 1000 rows

see reproducer attached. It should be run against ignite/examples/src/main/java/org/apache/ignite/examples/ExampleNodeStartup.java

Issue Links

• relates to: IGNITE-6217 Add benchmark to compare JDBC drivers and native SQL execution