[ACCUMULO-2801] define tablet syncs walog for each tablet in a batch

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.5.0, 1.5.1, 1.6.0
• Assignee: Unassigned
• Reporter: Keith Turner
• Created: 13/May/14 18:49
• Updated: 23/Apr/19 15:14
• Resolved: 23/Apr/19 15:14

Description

When the batch writer sends a batch of mutations for N tablets that were not currently using a walog, then define tablet will be called for each tablet. Define tablet will sync the walog. In hadoop 2 hsync is used, which is much slower than hadoop1 sync calls. If hsync takes 50ms and there are 100 tablets, then this operation would take 5 secs. The calls to define tablet do not occur frequently, just when walogs switch or tablets are loaded so the cost will be amortized. Ideally there could be one walog sync call for all of the tablets in a batch of mutations.

Issue Links

• duplicates: ACCUMULO-2175 Batch defining tablets in walog