lucene-solr-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hoss Man (JIRA)" <>
Subject [jira] Commented: (SOLR-829) replication Compression
Date Tue, 18 Nov 2008 06:23:44 GMT


Hoss Man commented on SOLR-829:

Let's keep this issue focused on one thing: making it possible to configure a "slave" solr
instance so that it indicates it can "Accept-Encoding" compressed responses during replication
(discussion of what the "master" does with that information are a separate matter)

>From my (naive) reading of the current patch, a few things jump out at me...

1) the "FastOutputStream" changes in ReplicationHandler looks like an unintentional part of
the patch.
2) why does setting the ZIP option to true disable checksums?  i'm not sure when/how checksums
are currently computed/compared, but if it can be done with a raw i/o streams right now, it
can be done with a GZIP i/o streams if the response is compressed.
3) the behavior of checkCompressed doesn't seem right. A Content-Encoding header is used to
indicate that the orriginal content has been compressed in order to transfer over HTTP, but
the Content-Type header is used to identify the true type of the payload.  we shouldn't silently
uncompress files just because they happen to have a mime type of "application/x-gzip-compressed".
 we might be able to get away with it in dealing with replication, but we shouldn't need it
(and unless i'm severaly mistaken, this will break in the event that gzip content is sent
*with* additional gzip Content-Encoding.

> replication Compression
> -----------------------
>                 Key: SOLR-829
>                 URL:
>             Project: Solr
>          Issue Type: Improvement
>          Components: replication (java)
>            Reporter: Simon Collins
>            Assignee: Shalin Shekhar Mangar
>         Attachments: email discussion.txt, solr-829.patch, solr-829.patch
> From a discussion on the mailing list solr-user, it would be useful to have an option
to compress the files sent between servers for replication purposes.
> Files sent across between indexes can be compressed by a large margin allowing for easier
replication between sites.
> ...Noted by Noble Paul 
> we will use a gzip on both ends of the pipe . On the slave side you can say <str name="zip">true<str>
as an extra option to compress and send data from server 
> Other thoughts on issue: 
> Do keep in mind that compression is a CPU intensive process so it is a trade off between
CPU utilization and network bandwidth.  I have see cases where compressing the data before
a network transfer ended up being slower than without compression because the cost of compression
and un-compression was more than the gain in network transfer.
> Why invent something when compression is standard in HTTP? --wunder

This message is automatically generated by JIRA.
You can reply to this email to add a comment to the issue online.

View raw message