[
https://issues.apache.org/jira/browse/OAK-4471?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15341626#comment-15341626
]
Ian Boston commented on OAK-4471:
---------------------------------
Compressing will obfuscate readability which will make it harder for deployers
to fix issues directly.
MongoDB already stores json as BSON.
MongoDB 3.2 recommends using the WiredTiger storage engine which has disk and
memory compression. Any benefits in compressing individual documents might be
minimal.
Minimising ratios between Application Domain Object -> JCR Node -> Oak Document
will have the largest impact. This current stands at 2 orders of magnitude for
an average application. (105x to be precise).
> More compact storage format for Documents
> -----------------------------------------
>
> Key: OAK-4471
> URL: https://issues.apache.org/jira/browse/OAK-4471
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: documentmk
> Reporter: Chetan Mehrotra
> Assignee: Chetan Mehrotra
> Labels: performance
> Fix For: 1.6
>
> Attachments: node-doc-size2.png
>
>
> Aim of this task is to evaluate storage cost of current approach for various
> Documents in DocumentNodeStore. And then evaluate possible alternative to see
> if we can get a significant reduction in storage size.
> Possible areas of improvement
> # NodeDocument
> ## Use binary encoding for property values - Currently property values are
> stored in JSON encoding i.e. arrays and single values are encoded in json
> along with there type
> ## Use binary encoding for Revision values - In a given document Revision
> instances are a major part of storage size. A binary encoding might provide
> more compact storage
> # Journal - The journal entries can be stored in compressed form
> Any new approach should support working with existing setups i.e. provide
> gradual change in storage format.
> *Possible Benefits*
> More compact storage would help in following ways
> # Low memory footprint of Document in Mongo and RDB
> # Low memory footprint for in memory NodeDocument instances - For e.g.
> property values when stored in binary format would consume less memory
> # Reduction in IO over wire - That should reduce the latency in say
> distributed deployments where Oak has to talk to remote primary
> Note that before doing any such change we must analyze the gains. Any change
> in encoding would make interpreting stored data harder and also represents
> significant change in stored data where we need to be careful to not
> introduce any bug!
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
