Flush Synced API

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Flush Synced Request

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A SyncedFlushRequest can be applied to one or more indices, or even on _all the indices:

SyncedFlushRequest request = new SyncedFlushRequest("index1"); 
SyncedFlushRequest requestMultiple = new SyncedFlushRequest("index1", "index2"); 
SyncedFlushRequest requestAll = new SyncedFlushRequest(); 

Flush synced one index

Flush synced multiple indices

Flush synced all the indices

Optional arguments

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request.indicesOptions(IndicesOptions.lenientExpandOpen()); 

Setting IndicesOptions controls how unavailable indices are resolved and how wildcard expressions are expanded

Synchronous Execution

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SyncedFlushResponse flushSyncedResponse = client.indices().flushSynced(request, RequestOptions.DEFAULT);

Asynchronous Execution

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The asynchronous execution of a flush request requires both the SyncedFlushRequest instance and an ActionListener instance to be passed to the asynchronous method:

client.indices().flushSyncedAsync(request, RequestOptions.DEFAULT, listener); 

The SyncedFlushRequest to execute and the ActionListener to use when the execution completes

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for SyncedFlushResponse looks like:

ActionListener<SyncedFlushResponse> listener = new ActionListener<SyncedFlushResponse>() {
    @Override
    public void onResponse(SyncedFlushResponse refreshResponse) {
        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

Called when the execution is successfully completed. The response is provided as an argument

Called in case of failure. The raised exception is provided as an argument

Flush Synced Response

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The returned SyncedFlushResponse allows to retrieve information about the executed operation as follows:

int totalShards = flushSyncedResponse.totalShards(); 
int successfulShards = flushSyncedResponse.successfulShards(); 
int failedShards = flushSyncedResponse.failedShards(); 

for (Map.Entry<String, SyncedFlushResponse.IndexResult> responsePerIndexEntry:
    flushSyncedResponse.getIndexResults().entrySet()) {
    String indexName = responsePerIndexEntry.getKey(); 
    SyncedFlushResponse.IndexResult indexResult = responsePerIndexEntry.getValue();
    int totalShardsForIndex = indexResult.totalShards(); 
    int successfulShardsForIndex = indexResult.successfulShards(); 
    int failedShardsForIndex = indexResult.failedShards(); 
    if (failedShardsForIndex > 0) {
        for (SyncedFlushResponse.ShardFailure failureEntry: indexResult.failures()) {
            int shardId = failureEntry.getShardId(); 
            String failureReason = failureEntry.getFailureReason(); 
            Map<String, Object> routing = failureEntry.getRouting(); 
        }
    }
}

Total number of shards hit by the flush request

Number of shards where the flush has succeeded

Number of shards where the flush has failed

Name of the index whose results we are about to calculate.

Total number of shards for index mentioned in 4.

Successful shards for index mentioned in 4.

Failed shards for index mentioned in 4.

One of the failed shard ids of the failed index mentioned in 4.

Reason for failure of copies of the shard mentioned in 8.

JSON represented by a Map<String, Object>. Contains shard related information like id, state, version etc. for the failed shard copies. If the entire shard failed then this returns an empty map.

By default, if the indices were not found, an ElasticsearchException will be thrown:

try {
    SyncedFlushRequest request = new SyncedFlushRequest("does_not_exist");
    client.indices().flushSynced(request, RequestOptions.DEFAULT);
} catch (ElasticsearchException exception) {
    if (exception.status() == RestStatus.NOT_FOUND) {
        
    }
}

Do something if the indices to be flushed were not found