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6 changes: 6 additions & 0 deletions docs/changelog/136889.yaml
Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
pr: 136889
summary: Remove early phase failure in batched
area: Search
type: bug
issues:
- 134151
3 changes: 0 additions & 3 deletions muted-tests.yml
Original file line number Diff line number Diff line change
Expand Up @@ -285,9 +285,6 @@ tests:
- class: org.elasticsearch.backwards.MixedClusterClientYamlTestSuiteIT
method: test {p0=mtermvectors/10_basic/Tests catching other exceptions per item}
issue: https://github.com/elastic/elasticsearch/issues/122414
- class: org.elasticsearch.search.SearchWithRejectionsIT
method: testOpenContextsAfterRejections
issue: https://github.com/elastic/elasticsearch/issues/130821
- class: org.elasticsearch.packaging.test.DockerTests
method: test090SecurityCliPackaging
issue: https://github.com/elastic/elasticsearch/issues/131107
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -48,13 +48,11 @@
import org.elasticsearch.search.query.QuerySearchResult;
import org.elasticsearch.tasks.CancellableTask;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.tasks.TaskCancelledException;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.AbstractTransportRequest;
import org.elasticsearch.transport.BytesTransportResponse;
import org.elasticsearch.transport.LeakTracker;
import org.elasticsearch.transport.SendRequestTransportException;
import org.elasticsearch.transport.Transport;
import org.elasticsearch.transport.TransportActionProxy;
import org.elasticsearch.transport.TransportChannel;
Expand Down Expand Up @@ -84,6 +82,9 @@ public class SearchQueryThenFetchAsyncAction extends AbstractSearchAsyncAction<S
private static final Logger logger = LogManager.getLogger(SearchQueryThenFetchAsyncAction.class);

private static final TransportVersion BATCHED_QUERY_PHASE_VERSION = TransportVersion.fromName("batched_query_phase_version");
private static final TransportVersion BATCHED_RESPONSE_MIGHT_INCLUDE_REDUCTION_FAILURE = TransportVersion.fromName(
"batched_response_might_include_reduction_failure"
);

private final SearchProgressListener progressListener;

Expand Down Expand Up @@ -225,20 +226,32 @@ public static final class NodeQueryResponse extends TransportResponse {
private final RefCounted refCounted = LeakTracker.wrap(new SimpleRefCounted());

private final Object[] results;
private final Exception reductionFailure;
private final SearchPhaseController.TopDocsStats topDocsStats;
private final QueryPhaseResultConsumer.MergeResult mergeResult;

public NodeQueryResponse(StreamInput in) throws IOException {
this.results = in.readArray(i -> i.readBoolean() ? new QuerySearchResult(i) : i.readException(), Object[]::new);
this.mergeResult = QueryPhaseResultConsumer.MergeResult.readFrom(in);
this.topDocsStats = SearchPhaseController.TopDocsStats.readFrom(in);
if (in.getTransportVersion().supports(BATCHED_RESPONSE_MIGHT_INCLUDE_REDUCTION_FAILURE) && in.readBoolean()) {
this.reductionFailure = in.readException();
this.mergeResult = null;
this.topDocsStats = null;
} else {
this.reductionFailure = null;
this.mergeResult = QueryPhaseResultConsumer.MergeResult.readFrom(in);
this.topDocsStats = SearchPhaseController.TopDocsStats.readFrom(in);
}
}

// public for tests
public Object[] getResults() {
return results;
}

Exception getReductionFailure() {
return reductionFailure;
}

@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeVInt(results.length);
Expand All @@ -249,7 +262,17 @@ public void writeTo(StreamOutput out) throws IOException {
writePerShardResult(out, (QuerySearchResult) result);
}
}
writeMergeResult(out, mergeResult, topDocsStats);
if (out.getTransportVersion().supports(BATCHED_RESPONSE_MIGHT_INCLUDE_REDUCTION_FAILURE)) {
boolean hasReductionFailure = reductionFailure != null;
out.writeBoolean(hasReductionFailure);
if (hasReductionFailure) {
out.writeException(reductionFailure);
} else {
writeMergeResult(out, mergeResult, topDocsStats);
}
} else {
writeMergeResult(out, mergeResult, topDocsStats);
}
}

@Override
Expand Down Expand Up @@ -502,7 +525,12 @@ public Executor executor() {
@Override
public void handleResponse(NodeQueryResponse response) {
if (results instanceof QueryPhaseResultConsumer queryPhaseResultConsumer) {
queryPhaseResultConsumer.addBatchedPartialResult(response.topDocsStats, response.mergeResult);
Exception reductionFailure = response.getReductionFailure();
if (reductionFailure != null) {
queryPhaseResultConsumer.failure.compareAndSet(null, reductionFailure);
} else {
queryPhaseResultConsumer.addBatchedPartialResult(response.topDocsStats, response.mergeResult);
}
}
for (int i = 0; i < response.results.length; i++) {
var s = request.shards.get(i);
Expand All @@ -526,21 +554,7 @@ public void handleResponse(NodeQueryResponse response) {
public void handleException(TransportException e) {
Exception cause = (Exception) ExceptionsHelper.unwrapCause(e);
logger.debug("handling node search exception coming from [" + nodeId + "]", cause);
if (e instanceof SendRequestTransportException || cause instanceof TaskCancelledException) {
// two possible special cases here where we do not want to fail the phase:
// failure to send out the request -> handle things the same way a shard would fail with unbatched execution
// as this could be a transient failure and partial results we may have are still valid
// cancellation of the whole batched request on the remote -> maybe we timed out or so, partial results may
// still be valid
onNodeQueryFailure(e, request, routing);
} else {
// Remote failure that wasn't due to networking or cancellation means that the data node was unable to reduce
// its local results. Failure to reduce always fails the phase without exception so we fail the phase here.
if (results instanceof QueryPhaseResultConsumer queryPhaseResultConsumer) {
queryPhaseResultConsumer.failure.compareAndSet(null, cause);
}
onPhaseFailure(getName(), "", cause);
}
onNodeQueryFailure(e, request, routing);
}
});
});
Expand Down Expand Up @@ -801,68 +815,80 @@ void onShardDone() {
if (countDown.countDown() == false) {
return;
}
RecyclerBytesStreamOutput out = null;
boolean success = false;
var channelListener = new ChannelActionListener<>(channel);
RecyclerBytesStreamOutput out = dependencies.transportService.newNetworkBytesStream();
out.setTransportVersion(channel.getVersion());
try (queryPhaseResultConsumer) {
var failure = queryPhaseResultConsumer.failure.get();
if (failure != null) {
handleMergeFailure(failure, channelListener, namedWriteableRegistry);
return;
}
final QueryPhaseResultConsumer.MergeResult mergeResult;
try {
mergeResult = Objects.requireNonNullElse(
queryPhaseResultConsumer.consumePartialMergeResultDataNode(),
EMPTY_PARTIAL_MERGE_RESULT
);
} catch (Exception e) {
handleMergeFailure(e, channelListener, namedWriteableRegistry);
return;
}
// translate shard indices to those on the coordinator so that it can interpret the merge result without adjustments,
// also collect the set of indices that may be part of a subsequent fetch operation here so that we can release all other
// indices without a roundtrip to the coordinating node
final BitSet relevantShardIndices = new BitSet(searchRequest.shards.size());
if (mergeResult.reducedTopDocs() != null) {
for (ScoreDoc scoreDoc : mergeResult.reducedTopDocs().scoreDocs) {
final int localIndex = scoreDoc.shardIndex;
scoreDoc.shardIndex = searchRequest.shards.get(localIndex).shardIndex;
relevantShardIndices.set(localIndex);
}
}
final int resultCount = queryPhaseResultConsumer.getNumShards();
out = dependencies.transportService.newNetworkBytesStream();
out.setTransportVersion(channel.getVersion());
try {
out.writeVInt(resultCount);
for (int i = 0; i < resultCount; i++) {
var result = queryPhaseResultConsumer.results.get(i);
if (result == null) {
NodeQueryResponse.writePerShardException(out, failures.remove(i));
} else {
// free context id and remove it from the result right away in case we don't need it anymore
maybeFreeContext(result, relevantShardIndices, namedWriteableRegistry);
NodeQueryResponse.writePerShardResult(out, result);
}
}
NodeQueryResponse.writeMergeResult(out, mergeResult, queryPhaseResultConsumer.topDocsStats);
success = true;
} catch (IOException e) {
handleMergeFailure(e, channelListener, namedWriteableRegistry);
return;
}
} finally {
if (success == false && out != null) {
out.close();
Exception reductionFailure = queryPhaseResultConsumer.failure.get();
if (reductionFailure == null) {
writeSuccessfulResponse(out);
} else {
writeReductionFailureResponse(out, reductionFailure);
}
} catch (IOException e) {
releaseAllResultsContexts();
channelListener.onFailure(e);
}
ActionListener.respondAndRelease(
channelListener,
new BytesTransportResponse(out.moveToBytesReference(), out.getTransportVersion())
);
}

private void writeSuccessfulResponse(RecyclerBytesStreamOutput out) throws IOException {
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Is it necessary to refactor this serialization code? Moving it around makes it more difficult to eye ball it somehow.

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disregard this previous comment. I understand why you did things the way you did. It's fine as-is. As for the review, I simply trust that the successful writing is a plain copy of the previous code we had, with no changes.

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That's right, same as the previous code except for the additional out.writeBoolean(false);, telling us there's no reduction failure.

final QueryPhaseResultConsumer.MergeResult mergeResult;
try {
mergeResult = Objects.requireNonNullElse(
queryPhaseResultConsumer.consumePartialMergeResultDataNode(),
EMPTY_PARTIAL_MERGE_RESULT
);
} catch (Exception e) {
writeReductionFailureResponse(out, e);
return;
}
// translate shard indices to those on the coordinator so that it can interpret the merge result without adjustments,
// also collect the set of indices that may be part of a subsequent fetch operation here so that we can release all other
// indices without a roundtrip to the coordinating node
final BitSet relevantShardIndices = new BitSet(searchRequest.shards.size());
if (mergeResult.reducedTopDocs() != null) {
for (ScoreDoc scoreDoc : mergeResult.reducedTopDocs().scoreDocs) {
final int localIndex = scoreDoc.shardIndex;
scoreDoc.shardIndex = searchRequest.shards.get(localIndex).shardIndex;
relevantShardIndices.set(localIndex);
}
}
final int resultCount = queryPhaseResultConsumer.getNumShards();
out.writeVInt(resultCount);
for (int i = 0; i < resultCount; i++) {
var result = queryPhaseResultConsumer.results.get(i);
if (result == null) {
NodeQueryResponse.writePerShardException(out, failures.remove(i));
} else {
// free context id and remove it from the result right away in case we don't need it anymore
maybeFreeContext(result, relevantShardIndices, namedWriteableRegistry);
NodeQueryResponse.writePerShardResult(out, result);
}
}
out.writeBoolean(false); // does not have a reduction failure
NodeQueryResponse.writeMergeResult(out, mergeResult, queryPhaseResultConsumer.topDocsStats);
}

private void writeReductionFailureResponse(RecyclerBytesStreamOutput out, Exception reductionFailure) throws IOException {
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Maybe add a comment about where the corresponding read code for this can be found? future readers may be looking for it and not easily finding it, due to the fact that we write to an opaque bytes transport response.

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Good idea, done.

final int resultCount = queryPhaseResultConsumer.getNumShards();
out.writeVInt(resultCount);
for (int i = 0; i < resultCount; i++) {
var result = queryPhaseResultConsumer.results.get(i);
if (result == null) {
NodeQueryResponse.writePerShardException(out, failures.remove(i));
} else {
NodeQueryResponse.writePerShardResult(out, result);
}
}
out.writeBoolean(true); // does have a reduction failure
out.writeException(reductionFailure);
releaseAllResultsContexts();
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should this be in a finally block ?

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In the case of an IOException, the caller releases contexts in a catch block. So I think this is alright, else we'll be releasing twice?

}

private void maybeFreeContext(
SearchPhaseResult result,
BitSet relevantShardIndices,
Expand All @@ -881,11 +907,7 @@ && isPartOfPIT(searchRequest.searchRequest, q.getContextId(), namedWriteableRegi
}
}

private void handleMergeFailure(
Exception e,
ChannelActionListener<TransportResponse> channelListener,
NamedWriteableRegistry namedWriteableRegistry
) {
private void releaseAllResultsContexts() {
queryPhaseResultConsumer.getSuccessfulResults()
.forEach(
searchPhaseResult -> releaseLocalContext(
Expand All @@ -895,7 +917,6 @@ private void handleMergeFailure(
namedWriteableRegistry
)
);
channelListener.onFailure(e);
}

void consumeResult(QuerySearchResult queryResult) {
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
9198000
2 changes: 1 addition & 1 deletion server/src/main/resources/transport/upper_bounds/9.3.csv
Original file line number Diff line number Diff line change
@@ -1 +1 @@
dimension_values,9197000
batched_response_might_include_reduction_failure,9198000