|
Diagnosing performance problems due to (possibly unintentional) updates to large records could be made easier if our documentation emphasized the following points:
- WiredTiger does no in-place updates, so large record sizes can cause much slower processing;
- Updates to large records can delay processing for that node as the update occurs (as it has to copy the memory from one place to another and write large records to the journal)
- This can result in high values of qr / qw / ar / aw, so if you see large values of qr / qw / ar / aw while issuing lots of updates, check that your documents are not growing to unbounded sizes.
|