[
https://issues.apache.org/jira/browse/SOLR-9038?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15263000#comment-15263000
]
Hrishikesh Gadre commented on SOLR-9038:
----------------------------------------
[~dsmiley] Sorry for the confusion. Yes it make sense to defer any "copying"
behavior to SOLR-5750. We can customize "backup functionality" to incorporate
this (e.g. ability to back up previously created snapshot). But from the
perspective of this JIRA, let's focus on indexed data only.
As you mentioned in your earlier comments, we can use the "commit" workflow to
create a named snapshot. But we still need a way to list the previously created
snapshots and an ability to delete the snapshots. Here the "delete snapshot"
functionality can just remove the corresponding index commit metadata. This way
during subsequent index merge, Lucene can perform the cleanup.
Does that make sense? If yes, I do have following questions
- How would the "list snapshots" and "delete snapshot" APIs look like? Do we
need to provide them just at the core level or at the collection level as well?
- Would we allow "destructive" operations (e.g. delete replica/shard) when we
have one or more snapshots?
- It seems to me that the "commit" request will be executed by all replicas for
a given collection. What should happen when a "commit" request can not be
processed by a replica (since it may be down) ? We may need to ensure that
during the replica "recovery" it also fetches the information about commit
metadata.
> Ability to create/delete/list snapshots for a solr collection
> -------------------------------------------------------------
>
> Key: SOLR-9038
> URL: https://issues.apache.org/jira/browse/SOLR-9038
> Project: Solr
> Issue Type: New Feature
> Components: SolrCloud
> Reporter: Hrishikesh Gadre
>
> Currently work is under-way to implement backup/restore API for Solr cloud
> (SOLR-5750). SOLR-5750 is about providing an ability to "copy" index files
> and collection metadata to a configurable location.
> In addition to this, we should also provide a facility to create "named"
> snapshots for Solr collection. Here by "snapshot" I mean configuring the
> underlying Lucene IndexDeletionPolicy to not delete a specific commit point
> (e.g. using PersistentSnapshotIndexDeletionPolicy). This should not be
> confused with SOLR-5340 which implements core level "backup" functionality.
> The primary motivation of this feature is to decouple recording/preserving a
> known consistent state of a collection from actually "copying" the relevant
> files to a physically separate location. This decoupling have number of
> advantages
> - We can use specialized data-copying tools for transferring Solr index
> files. e.g. in Hadoop environment, typically
> [distcp|https://hadoop.apache.org/docs/r1.2.1/distcp2.html] tool is used to
> copy files from one location to other. This tool provides various options to
> configure degree of parallelism, bandwidth usage as well as integration with
> different types and versions of file systems (e.g. AWS S3, Azure Blob store
> etc.)
> - This separation of concern would also help Solr to focus on the key
> functionality (i.e. querying and indexing) while delegating the copy
> operation to the tools built for that purpose.
> - Users can decide if/when to copy the data files as against creating a
> snapshot. e.g. a user may want to create a snapshot of a collection before
> making an experimental change (e.g. updating/deleting docs, schema change
> etc.). If the experiment is successful, he can delete the snapshot (without
> having to copy the files). If the experiment is failed, then he can copy the
> files associated with the snapshot and restore.
> Note that Apache Blur project is also providing a similar feature
> [BLUR-132|https://issues.apache.org/jira/browse/BLUR-132]
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: dev-h...@lucene.apache.org
