[CASSANDRA-2401] getColumnFamily() return null, which is not checked in ColumnFamilyStore.java scan() method, causing Timeout Exception in query

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 0.7.6

Environment

Hector 0.7.0-28, Cassandra 0.7.4, Windows 7, Eclipse

• Severity: Normal
• Assignee: Jonathan Ellis
• Reporter: Tey Kar Shiang

Authors

Jonathan Ellis

Reviewers

Sylvain Lebresne

• Created: 29/Mar/11 07:15
• Updated: 16/Apr/19 09:33
• Resolved: 14/May/11 15:03

Description

ColumnFamilyStore.java, line near 1680, "ColumnFamily data = getColumnFamily(new QueryFilter(dk, path, firstFilter))", the data is returned null, causing NULL exception in "satisfies(data, clause, primary)" which is not captured. The callback got timeout and return a Timeout exception to Hector.

The data is empty, as I traced, I have the the columns Count as 0 in removeDeletedCF(), which return the null there. (I am new and trying to understand the logics around still). Instead of crash to NULL, could we bypass the data?

About my test:
A stress-test program to add, modify and delete data to keyspace. I have 30 threads simulate concurrent users to perform the actions above, and do a query to all rows periodically. I have Column Family with rows (as File) and columns as index (e.g. userID, fileType).

No issue on the first day of test, and stopped for 3 days. I restart the test on 4th day, 1 of the users failed to query the files (timeout exception received). Most of the users are still okay with the query.