[HDFS-5788] listLocatedStatus response can be very large

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.10, 2.2.0, 3.0.0-alpha1
• Fix Version/s: 2.3.0
• Component/s: namenode
• Hadoop Flags: Reviewed
• Assignee: Nathan Roberts
• Reporter: Nathan Roberts
• Created: 16/Jan/14 15:27
• Updated: 12/May/16 18:18
• Resolved: 23/Jan/14 17:04

Description

Currently we limit the size of listStatus requests to a default of 1000 entries. This works fine except in the case of listLocatedStatus where the location information can be quite large. As an example, a directory with 7000 entries, 4 blocks each, 3 way replication - a listLocatedStatus response is over 1MB. This can chew up very large amounts of memory in the NN if lots of clients try to do this simultaneously.

Seems like it would be better if we also considered the amount of location information being returned when deciding how many files to return.

Patch will follow shortly.

Issue Links

• relates to: HADOOP-8942 Thundering herd of RPCs with large responses leads to OOM