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HDDS-9198. Maintain local cache in OMSnapshotPurgeRequest to get upda…
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…ted snapshotInfo and pass the same to OMSnapshotPurgeResponse (apache#7045)

(cherry picked from commit be34303)
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@hemantk-12
hemantk-12 authored and pony.chen committed Sep 15, 2024
1 parent 2711d03 commit 1906009
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Showing 2 changed files with 36 additions and 50 deletions.
78 changes: 35 additions & 43 deletions ...ger/src/main/java/org/apache/hadoop/ozone/om/request/snapshot/OMSnapshotPurgeRequest.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@

package org.apache.hadoop.ozone.om.request.snapshot;

import org.apache.hadoop.ozone.om.OMMetadataManager;
import org.apache.hadoop.ozone.om.OMMetrics;
import org.apache.hadoop.hdds.utils.db.cache.CacheKey;
import org.apache.hadoop.hdds.utils.db.cache.CacheValue;
Expand Down Expand Up @@ -53,6 +54,13 @@ public class OMSnapshotPurgeRequest extends OMClientRequest {

private static final Logger LOG = LoggerFactory.getLogger(OMSnapshotPurgeRequest.class);

/**
* This map contains up to date snapshotInfo and works as a local cache for OMSnapshotPurgeRequest.
* Since purge and other updates happen in sequence inside validateAndUpdateCache, we can get updated snapshotInfo
* from this map rather than getting form snapshotInfoTable which creates a deep copy for every get call.
*/
private final Map<String, SnapshotInfo> updatedSnapshotInfos = new HashMap<>();

public OMSnapshotPurgeRequest(OMRequest omRequest) {
super(omRequest);
}
Expand All @@ -78,9 +86,6 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
try {
List<String> snapshotDbKeys = snapshotPurgeRequest
.getSnapshotDBKeysList();
Map<String, SnapshotInfo> updatedSnapInfos = new HashMap<>();
Map<String, SnapshotInfo> updatedPathPreviousAndGlobalSnapshots =
new HashMap<>();

// Each snapshot purge operation does three things:
// 1. Update the deep clean flag for the next active snapshot (So that it can be
Expand All @@ -90,7 +95,7 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
// There is no need to take lock for snapshot purge as of now. We can simply rely on OMStateMachine
// because it executes transaction sequentially.
for (String snapTableKey : snapshotDbKeys) {
SnapshotInfo fromSnapshot = omMetadataManager.getSnapshotInfoTable().get(snapTableKey);
SnapshotInfo fromSnapshot = getUpdatedSnapshotInfo(snapTableKey, omMetadataManager);
if (fromSnapshot == null) {
// Snapshot may have been purged in the previous iteration of SnapshotDeletingService.
LOG.warn("The snapshot {} is not longer in snapshot table, It maybe removed in the previous " +
Expand All @@ -102,25 +107,21 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
SnapshotUtils.getNextActiveSnapshot(fromSnapshot, snapshotChainManager, omSnapshotManager);

// Step 1: Update the deep clean flag for the next active snapshot
updateSnapshotInfoAndCache(nextSnapshot, omMetadataManager, trxnLogIndex, updatedSnapInfos);
updateSnapshotInfoAndCache(nextSnapshot, omMetadataManager, trxnLogIndex);
// Step 2: Update the snapshot chain.
updateSnapshotChainAndCache(omMetadataManager, fromSnapshot, trxnLogIndex,
updatedPathPreviousAndGlobalSnapshots);
updateSnapshotChainAndCache(omMetadataManager, fromSnapshot, trxnLogIndex);
// Remove and close snapshot's RocksDB instance from SnapshotCache.
omSnapshotManager.invalidateCacheEntry(fromSnapshot.getSnapshotId());
// Step 3: Purge the snapshot from SnapshotInfoTable cache.
omMetadataManager.getSnapshotInfoTable()
.addCacheEntry(new CacheKey<>(fromSnapshot.getTableKey()), CacheValue.get(trxnLogIndex));
}

omClientResponse = new OMSnapshotPurgeResponse(omResponse.build(),
snapshotDbKeys, updatedSnapInfos,
updatedPathPreviousAndGlobalSnapshots);
omClientResponse = new OMSnapshotPurgeResponse(omResponse.build(), snapshotDbKeys, updatedSnapshotInfos);

omMetrics.incNumSnapshotPurges();
LOG.info("Successfully executed snapshotPurgeRequest: {{}} along with updating deep clean flags for " +
"snapshots: {} and global and previous for snapshots:{}.",
snapshotPurgeRequest, updatedSnapInfos.keySet(), updatedPathPreviousAndGlobalSnapshots.keySet());
LOG.info("Successfully executed snapshotPurgeRequest: {{}} along with updating snapshots:{}.",
snapshotPurgeRequest, updatedSnapshotInfos);
} catch (IOException ex) {
omClientResponse = new OMSnapshotPurgeResponse(
createErrorOMResponse(omResponse, ex));
Expand All @@ -131,9 +132,8 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
return omClientResponse;
}

private void updateSnapshotInfoAndCache(SnapshotInfo snapInfo,
OmMetadataManagerImpl omMetadataManager, long trxnLogIndex,
Map<String, SnapshotInfo> updatedSnapInfos) throws IOException {
private void updateSnapshotInfoAndCache(SnapshotInfo snapInfo, OmMetadataManagerImpl omMetadataManager,
long trxnLogIndex) throws IOException {
if (snapInfo != null) {
// Setting next snapshot deep clean to false, Since the
// current snapshot is deleted. We can potentially
Expand All @@ -143,7 +143,7 @@ private void updateSnapshotInfoAndCache(SnapshotInfo snapInfo,
// Update table cache first
omMetadataManager.getSnapshotInfoTable().addCacheEntry(new CacheKey<>(snapInfo.getTableKey()),
CacheValue.get(trxnLogIndex, snapInfo));
updatedSnapInfos.put(snapInfo.getTableKey(), snapInfo);
updatedSnapshotInfos.put(snapInfo.getTableKey(), snapInfo);
}
}

Expand All @@ -156,8 +156,7 @@ private void updateSnapshotInfoAndCache(SnapshotInfo snapInfo,
private void updateSnapshotChainAndCache(
OmMetadataManagerImpl metadataManager,
SnapshotInfo snapInfo,
long trxnLogIndex,
Map<String, SnapshotInfo> updatedPathPreviousAndGlobalSnapshots
long trxnLogIndex
) throws IOException {
if (snapInfo == null) {
return;
Expand Down Expand Up @@ -196,43 +195,36 @@ private void updateSnapshotChainAndCache(
}

SnapshotInfo nextPathSnapInfo =
nextPathSnapshotKey != null ? metadataManager.getSnapshotInfoTable().get(nextPathSnapshotKey) : null;
nextPathSnapshotKey != null ? getUpdatedSnapshotInfo(nextPathSnapshotKey, metadataManager) : null;

SnapshotInfo nextGlobalSnapInfo =
nextGlobalSnapshotKey != null ? metadataManager.getSnapshotInfoTable().get(nextGlobalSnapshotKey) : null;

// Updates next path snapshot's previous snapshot ID
if (nextPathSnapInfo != null) {
nextPathSnapInfo.setPathPreviousSnapshotId(snapInfo.getPathPreviousSnapshotId());
metadataManager.getSnapshotInfoTable().addCacheEntry(
new CacheKey<>(nextPathSnapInfo.getTableKey()),
CacheValue.get(trxnLogIndex, nextPathSnapInfo));
updatedPathPreviousAndGlobalSnapshots
.put(nextPathSnapInfo.getTableKey(), nextPathSnapInfo);
}

// Updates next global snapshot's previous snapshot ID
// If both next global and path snapshot are same, it may overwrite
// nextPathSnapInfo.setPathPreviousSnapshotID(), adding this check
// will prevent it.
if (nextGlobalSnapInfo != null && nextPathSnapInfo != null &&
nextGlobalSnapInfo.getSnapshotId().equals(nextPathSnapInfo.getSnapshotId())) {
nextPathSnapInfo.setGlobalPreviousSnapshotId(snapInfo.getGlobalPreviousSnapshotId());
metadataManager.getSnapshotInfoTable().addCacheEntry(
new CacheKey<>(nextPathSnapInfo.getTableKey()),
CacheValue.get(trxnLogIndex, nextPathSnapInfo));
updatedPathPreviousAndGlobalSnapshots
.put(nextPathSnapInfo.getTableKey(), nextPathSnapInfo);
} else if (nextGlobalSnapInfo != null) {
nextGlobalSnapInfo.setGlobalPreviousSnapshotId(
snapInfo.getGlobalPreviousSnapshotId());
SnapshotInfo nextGlobalSnapInfo =
nextGlobalSnapshotKey != null ? getUpdatedSnapshotInfo(nextGlobalSnapshotKey, metadataManager) : null;

if (nextGlobalSnapInfo != null) {
nextGlobalSnapInfo.setGlobalPreviousSnapshotId(snapInfo.getGlobalPreviousSnapshotId());
metadataManager.getSnapshotInfoTable().addCacheEntry(
new CacheKey<>(nextGlobalSnapInfo.getTableKey()),
CacheValue.get(trxnLogIndex, nextGlobalSnapInfo));
updatedPathPreviousAndGlobalSnapshots
.put(nextGlobalSnapInfo.getTableKey(), nextGlobalSnapInfo);
}

snapshotChainManager.deleteSnapshot(snapInfo);
}

private SnapshotInfo getUpdatedSnapshotInfo(String snapshotTableKey, OMMetadataManager omMetadataManager)
throws IOException {
SnapshotInfo snapshotInfo = updatedSnapshotInfos.get(snapshotTableKey);

if (snapshotInfo == null) {
snapshotInfo = omMetadataManager.getSnapshotInfoTable().get(snapshotTableKey);
updatedSnapshotInfos.put(snapshotTableKey, snapshotInfo);
}
return snapshotInfo;
}
}
8 changes: 1 addition & 7 deletions ...r/src/main/java/org/apache/hadoop/ozone/om/response/snapshot/OMSnapshotPurgeResponse.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,18 +48,15 @@ public class OMSnapshotPurgeResponse extends OMClientResponse {
LoggerFactory.getLogger(OMSnapshotPurgeResponse.class);
private final List<String> snapshotDbKeys;
private final Map<String, SnapshotInfo> updatedSnapInfos;
private final Map<String, SnapshotInfo> updatedPreviousAndGlobalSnapInfos;

public OMSnapshotPurgeResponse(
@Nonnull OMResponse omResponse,
@Nonnull List<String> snapshotDbKeys,
Map<String, SnapshotInfo> updatedSnapInfos,
Map<String, SnapshotInfo> updatedPreviousAndGlobalSnapInfos
Map<String, SnapshotInfo> updatedSnapInfos
) {
super(omResponse);
this.snapshotDbKeys = snapshotDbKeys;
this.updatedSnapInfos = updatedSnapInfos;
this.updatedPreviousAndGlobalSnapInfos = updatedPreviousAndGlobalSnapInfos;
}

/**
Expand All @@ -71,7 +68,6 @@ public OMSnapshotPurgeResponse(@Nonnull OMResponse omResponse) {
checkStatusNotOK();
this.snapshotDbKeys = null;
this.updatedSnapInfos = null;
this.updatedPreviousAndGlobalSnapInfos = null;
}

@Override
Expand All @@ -81,8 +77,6 @@ protected void addToDBBatch(OMMetadataManager omMetadataManager,
OmMetadataManagerImpl metadataManager = (OmMetadataManagerImpl)
omMetadataManager;
updateSnapInfo(metadataManager, batchOperation, updatedSnapInfos);
updateSnapInfo(metadataManager, batchOperation,
updatedPreviousAndGlobalSnapInfos);
for (String dbKey: snapshotDbKeys) {
// Skip the cache here because snapshot is purged from cache in OMSnapshotPurgeRequest.
SnapshotInfo snapshotInfo = omMetadataManager
Expand Down

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