[THRIFT-788] thrift_protocol.so: multiget/multiget_slice does not handle more than 17 keys correctly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: 0.7
• Component/s: PHP - Library
• Labels: multiget multiget_slice php thrift_protocol

Environment

• ubuntu 10.04 32bit
• thrift svn
• php-5.3.2 with thrift_protocol.so 1.0 enabled
• cassandra 0.6+0.7/trunk

• Assignee: Nicholas Telford
• Reporter: Alexander Liemen
• Created: 24/May/10 16:02
• Updated: 10/Aug/11 18:27
• Resolved: 11/Apr/11 15:46

Description

thrift_protocol.so does not handle multiget/multiget_slice with more than 17 keys correctly. The query time sky rockets from 10ms to a steady 900ms starting with 18 keys. It doesn't matter if you fetch 18 or 50. Solid 900ms...

The bug can easily + steadily be reproduced:

• standard Keyspace1 / CF Standard1 setup
• name: Keyspace1
  replica_placement_strategy: org.apache.cassandra.locator.RackUnawareStrategy
  replication_factor: 1
  column_families:
• name: Standard1
  compare_with: BytesType

• insert e.g. 1000 columns email:value / testmail1-testmail1000 with key = 1...1000

• $keys=array('1','2',.....'17')
• $client->multiget_slice($keys,$columnParent,$predicate,$consistency_level); -> 10ms

• $keys=array('1','2',.....'18')
• $client->multiget_slice($keys,$columnParent,$predicate,$consistency_level); -> 900ms

• $keys=array('1','2',.....'100')
• $client->multiget_slice($keys,$columnParent,$predicate,$consistency_level); -> 900ms

It does return the right columns though.

It can easily be fixed: disable thrift_protocol.so

This might be a 32bit microseconds issue. Still very strange though.

Issue Links

• is blocked by: THRIFT-638 BufferedTransport + C extensions block until recv timeout is reached on last fread call