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Change randomized prefix to contain only hex characters #13799

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Merged
arhimondr merged 1 commit into from
Aug 23, 2022
Merged

Change randomized prefix to contain only hex characters #13799

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19 changes: 11 additions & 8 deletions ...ange-filesystem/src/main/java/io/trino/plugin/exchange/filesystem/FileSystemExchange.java
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Original file line number Diff line number Diff line change
Expand Up @@ -67,8 +67,8 @@ public class FileSystemExchange
implements Exchange
{
private static final Pattern PARTITION_FILE_NAME_PATTERN = Pattern.compile("(\\d+)_(\\d+)\\.data");
private static final char[] RANDOMIZED_PREFIX_ALPHABET = "abcdefghijklmnopqrstuvwzyz0123456789".toCharArray();
private static final int RANDOMIZED_PREFIX_LENGTH = 6;
private static final char[] RANDOMIZED_HEX_PREFIX_ALPHABET = "abcdef0123456789".toCharArray();
private static final int RANDOMIZED_HEX_PREFIX_LENGTH = 6;

private final List<URI> baseDirectories;
private final FileSystemExchangeStorage exchangeStorage;
Expand Down Expand Up @@ -257,11 +257,11 @@ private ListenableFuture<Multimap<Integer, FileStatus>> getCommittedPartitions(i
private URI getTaskOutputDirectory(int taskPartitionId)
{
URI baseDirectory = baseDirectories.get(taskPartitionId % baseDirectories.size());
String randomizedPrefix = randomizedPrefixes.computeIfAbsent(taskPartitionId, ignored -> generateRandomizedPrefix());
String randomizedHexPrefix = randomizedPrefixes.computeIfAbsent(taskPartitionId, ignored -> generateRandomizedHexPrefix());

// Add a randomized prefix to evenly distribute data into different S3 shards
// Data output file path format: {randomizedPrefix}.{queryId}.{stageId}.{sinkPartitionId}/{attemptId}/{sourcePartitionId}_{splitId}.data
return baseDirectory.resolve(randomizedPrefix + "." + exchangeContext.getQueryId() + "." + exchangeContext.getExchangeId() + "." + taskPartitionId + PATH_SEPARATOR);
// Data output file path format: {randomizedHexPrefix}.{queryId}.{stageId}.{sinkPartitionId}/{attemptId}/{sourcePartitionId}_{splitId}.data
return baseDirectory.resolve(randomizedHexPrefix + "." + exchangeContext.getQueryId() + "." + exchangeContext.getExchangeId() + "." + taskPartitionId + PATH_SEPARATOR);
}

@Override
Expand Down Expand Up @@ -314,11 +314,14 @@ public void close()
stats.getCloseExchange().record(exchangeStorage.deleteRecursively(allSinks.stream().map(this::getTaskOutputDirectory).collect(toImmutableList())));
}

private static String generateRandomizedPrefix()
/**
* Some storage systems prefer the prefix to be hexadecimal characters
*/
private static String generateRandomizedHexPrefix()
{
char[] value = new char[RANDOMIZED_PREFIX_LENGTH];
char[] value = new char[RANDOMIZED_HEX_PREFIX_LENGTH];
for (int i = 0; i < value.length; i++) {
value[i] = RANDOMIZED_PREFIX_ALPHABET[ThreadLocalRandom.current().nextInt(RANDOMIZED_PREFIX_ALPHABET.length)];
value[i] = RANDOMIZED_HEX_PREFIX_ALPHABET[ThreadLocalRandom.current().nextInt(RANDOMIZED_HEX_PREFIX_ALPHABET.length)];
}
return new String(value);
}
Expand Down