HBASE-28805: Chunked persistence of backing map for persistent bucket cache. #6183
Conversation
This file contains 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
|
💔 -1 overall
This message was automatically generated. |
wchevreuil
reviewed
Aug 29, 2024
Comment on lines
1369
to
1386
| byte[] convertToBytes (long value) { | ||
| byte[] bytes = new byte[Long.BYTES]; | ||
| int length = bytes.length; | ||
| for (int i = 0; i < length; i++) { | ||
| bytes[length - i - 1] = (byte) (value & 0xFF); | ||
| value >>= 8; | ||
| } | ||
| return bytes; | ||
| } | ||
|
|
||
| long convertToLong(byte[] bytes) { | ||
| long value = 0; | ||
| for (byte b : bytes) { | ||
| value = (value << 8) + (b & 0xFF); | ||
| } | ||
| return value; | ||
| } | ||
|
|
There was a problem hiding this comment.
There are already Bytes.toBytes, Bytes.toLong for this.
There was a problem hiding this comment.
ok, let me use those.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
Outdated
Show resolved
Hide resolved
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
Outdated
Show resolved
Hide resolved
| int blockCount = 0; | ||
| int chunkCount = 0; | ||
|
|
||
| BucketCacheProtos.BackingMap.Builder builder = BucketCacheProtos.BackingMap.newBuilder(); |
There was a problem hiding this comment.
Why are we creating proto builder here? Can't this go to BucketProtoUtils?
|
🎊 +1 overall
This message was automatically generated. |
… cache. The persistent bucket cache implementation feature relies on the persistence of backing map to a persistent file. the protobuf APIs are used to serialise the backing map and its related structures into the file. An asynchronous thread periodically flushes the contents of backing map to the persistence file. The protobuf library has a limitation of 2GB on the size of protobuf messages. If the size of backing map increases beyond 2GB, an unexpected exception is reported in the asynchronous thread and stops the persister thread. This causes the persistent file go out of sync with the actual bucket cache. Due to this, the bucket cache shrinks to a smaller size after a cache restart. Checksum errors are also reported. This Jira tracks the implementation of introducing chunking of the backing map to persistence such that every protobuf is smaller than 2GB in size. Change-Id: I8623ad2eaf1d1a56f96bc3120b14e5229ae55c42
wchevreuil
reviewed
Aug 29, 2024
| .setChecksum(ByteString | ||
| .copyFrom(((PersistentIOEngine) cache.ioEngine).calculateChecksum(cache.getAlgorithm()))) | ||
| .build(); | ||
| } | ||
|
|
||
| private static BucketCacheProtos.BackingMap toPB(Map<BlockCacheKey, BucketEntry> backingMap) { | ||
| static void toPB(BucketCache cache, FileOutputStream fos, long chunkSize) throws IOException{ |
There was a problem hiding this comment.
nit: We should rename it to serializeAsPB.
Comment on lines
1564
to
1575
| fos.write(PB_MAGIC_V2); | ||
| long numChunks = backingMap.size() / persistenceChunkSize; | ||
| if (backingMap.size() % persistenceChunkSize != 0) { | ||
| numChunks += 1; | ||
| } | ||
|
|
||
| LOG.debug("persistToFile: before persisting backing map size: {}, " | ||
| + "fullycachedFiles size: {}, chunkSize: {}, numberofChunks: {}", | ||
| backingMap.size(), fullyCachedFiles.size(), persistenceChunkSize, numChunks); | ||
|
|
||
| fos.write(Bytes.toBytes(persistenceChunkSize)); | ||
| fos.write(Bytes.toBytes(numChunks)); |
There was a problem hiding this comment.
Since we are already passing the output stream to BucketProtoUtils, who's now also responsible for serialization, can we just move everything there?
|
💔 -1 overall
This message was automatically generated. |
Change-Id: I3eaddcef94a711e63eeefd47063f074d0a57c984
|
🎊 +1 overall
This message was automatically generated. |
|
💔 -1 overall
This message was automatically generated. |
|
🎊 +1 overall
This message was automatically generated. |
Change-Id: I082a83ef841125eed00d3ccd660bd2beb95dc4f9
jhungund
force-pushed
the
HBASE-28805
branch
from
00963f0 to
f853dbc
Compare
|
🎊 +1 overall
This message was automatically generated. |
|
🎊 +1 overall
This message was automatically generated. |
jhungund
added a commit
to jhungund/hbase
that referenced
this pull request
Sep 4, 2024
… cache. (apache#6183) HBASE-28805: Chunked persistence of backing map for persistent bucket cache. Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org> Change-Id: I72efe71040a8970f87a8b2a08c4c4ac1ceef74bc
jhungund
added a commit
to jhungund/hbase
that referenced
this pull request
Sep 4, 2024
… cache. (apache#6183) HBASE-28805: Chunked persistence of backing map for persistent bucket cache. Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org> Change-Id: I72efe71040a8970f87a8b2a08c4c4ac1ceef74bc
jhungund
added a commit
to jhungund/hbase
that referenced
this pull request
Sep 6, 2024
… cache. (apache#6183) HBASE-28805: Chunked persistence of backing map for persistent bucket cache. Signed-off-by: Wellington Chevreuil <wchevreuil@apache.org> Change-Id: I72efe71040a8970f87a8b2a08c4c4ac1ceef74bc
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
The persistent bucket cache implementation feature relies on the persistence of backing map to a persistent file. the protobuf APIs are used to serialise the backing map and its related structures into the file.
An asynchronous thread periodically flushes the contents of backing map to the persistence file.
The protobuf library has a limitation of 2GB on the size of protobuf messages. If the size of backing map increases beyond 2GB, an unexpected exception is reported in the asynchronous thread and stops the persister thread. This causes the persistent file go out of sync with the actual bucket cache. Due to this, the bucket cache shrinks to a smaller size after a cache restart. Checksum errors are also reported.
This Jira tracks the implementation of introducing chunking of the backing map to persistence such that every protobuf is smaller than 2GB in size.
Change-Id: I8623ad2eaf1d1a56f96bc3120b14e5229ae55c42