Save Memory on Large Repository Metadata Blob Writes#74693
Merged
original-brownbear merged 2 commits intoelastic:7.xfrom Jun 29, 2021
original-brownbear:74313-7.x
Merged
Save Memory on Large Repository Metadata Blob Writes#74693original-brownbear merged 2 commits intoelastic:7.xfrom original-brownbear:74313-7.x
original-brownbear merged 2 commits intoelastic:7.xfrom
original-brownbear:74313-7.x
Conversation
Extracted the chunked output stream logic from #74313 and added tests for it to make it easier to review.
This PR adds a new API for doing streaming serialization writes to a repository to enable repository metadata of arbitrary size and at bounded memory during writing. The existing write-APIs require knowledge of the eventual blob size beforehand. This forced us to materialize the serialized blob in memory before writing, costing a lot of memory in case of e.g. very large `RepositoryData` (and limiting us to `2G` max blob size). With this PR the requirement to fully materialize the serialized metadata goes away and the memory overhead becomes completely bounded by the outbound buffer size of the repository implementation. As we move to larger repositories this makes master node stability a lot more predictable since writing out `RepositoryData` does not take as much memory any longer (same applies to shard level metadata), enables aggregating multiple metadata blobs into a single larger blobs without massive overhead and removes the 2G size limit on `RepositoryData`.
Collaborator
|
Pinging @elastic/es-distributed (Team:Distributed) |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR adds a new API for doing streaming serialization writes to a repository to enable repository metadata of arbitrary size and at bounded memory during writing.
The existing write-APIs require knowledge of the eventual blob size beforehand. This forced us to materialize the serialized blob in memory before writing, costing a lot of memory in case of e.g. very large
RepositoryData(and limiting us to2Gmax blob size).With this PR the requirement to fully materialize the serialized metadata goes away and the memory overhead becomes completely bounded by the outbound buffer size of the repository implementation.
As we move to larger repositories this makes master node stability a lot more predictable since writing out
RepositoryDatadoes not take as much memory any longer (same applies to shard level metadata), enables aggregating multiple metadata blobs into a single larger blobs without massive overhead and removes the 2G size limit onRepositoryData.backport of #74313 and #74620