[GitHub] nickva opened a new pull request #846: Clean up replicator logs

[gi...@git.apache.org]

nickva opened a new pull request #846: Clean up replicator logs
URL: https://github.com/apache/couchdb/pull/846
 
 
   Previously replicator was unnesessarily verbose during crashes. This commit
   reduces the vorbosity and make the error messages more helpful.
   
   Most of the replication failures happen in the startup phase when both target
   and source are opened. That's a good place to handle common errors, and there
   were a few already handled (db not found, lack of authorization). This commit
   adds another other common one - inability to resolve endpoint host names. This
   covers cases were there user mistypes the host name or there is a DNS issue.
   
   Also during the startup phase, if an error occurs a stacktrace was logged in
   addition to the whole state of the #rep{} record. Most of the rep record and
   the stack are not that useful compared to how much noise it generates. So
   instead, log only a few relevant fields from #rep{} and only the top 2 stack
   frames. Combined with dns lookup failure this change results in almost a 4x
   (2KB vs 500B) reduction in log noise while providing better debugging
   information.
   
   One last source of excessive log noise the dumping of the full replicator job
   state during crashes. This included both the #rep and the #rep_state records.
   Those have a lot of redundnat information, and since they are dumped as tuples,
   it was hard to use and find the values of each individual field. In this case
   `format_status/2` was improved to dump only a selected set of field along with
   their names. This results in another 3x reduction in log noise.
   
 
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services