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add hard limit for FastSerdeCache #82

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add hard limit for FastSerdeCache #82

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91 changes: 77 additions & 14 deletions avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeCache.java
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Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,20 @@ public final class FastSerdeCache {

private static volatile FastSerdeCache _INSTANCE;

/**
* Fast-avro will generate and load serializer and deserializer(SerDes) classes into metaspace during runtime.
* During serialization and deserialization, fast-avro also leverages JIT compilation to boost the SerDes speed.
* And JIT compilation code is saved in code cache.
* Too much usage of metaspace and code cache will bring GC/OOM issue.
*
* We set a hard limit of the total number of SerDes classes generated and loaded by fast-avro.
* By default, the limit is set to MAX_INT.
* Fast-avro will fall back to regular avro after the limit is hit.
* One could set the limit through {@link FastSerdeCache} constructors.
*/
private volatile int generatedFastSerDesLimit = Integer.MAX_VALUE;
private final AtomicInteger generatedSerDesNum = new AtomicInteger(0);

private final Map<String, FastDeserializer<?>> fastSpecificRecordDeserializersCache =
new FastAvroConcurrentHashMap<>();
private final Map<String, FastDeserializer<?>> fastGenericRecordDeserializersCache =
Expand Down Expand Up @@ -81,6 +95,20 @@ public FastSerdeCache(Executor executorService, Supplier<String> compileClassPat
this(executorService, compileClassPathSupplier.get());
}

/**
*
* @param executorService
* {@link Executor} used by serializer/deserializer compile threads
* @param compileClassPathSupplier
* custom classpath {@link Supplier}
* @param limit
* custom number {@link #generatedFastSerDesLimit}
*/
public FastSerdeCache(Executor executorService, Supplier<String> compileClassPathSupplier, int limit) {
this(executorService, compileClassPathSupplier);
this.generatedFastSerDesLimit = limit;
}

public FastSerdeCache(String compileClassPath) {
this();
this.compileClassPath = Optional.ofNullable(compileClassPath);
Expand Down Expand Up @@ -122,6 +150,15 @@ private FastSerdeCache() {
this((Executor) null);
}

/**
* @param limit
* custom number {@link #generatedFastSerDesLimit}
*/
public FastSerdeCache(int limit) {
this();
this.generatedFastSerDesLimit = limit;
}

/**
* Gets default {@link FastSerdeCache} instance. Default instance classpath can be customized via
* {@value #CLASSPATH} or {@value #CLASSPATH_SUPPLIER} system properties.
Expand Down Expand Up @@ -206,10 +243,11 @@ public FastDeserializer<?> getFastSpecificDeserializer(Schema writerSchema, Sche
new FastDeserializerWithAvroSpecificImpl<>(writerSchema, readerSchema));
if (deserializer == null) {
deserializer = fastSpecificRecordDeserializersCache.get(schemaKey);
CompletableFuture.supplyAsync(() -> buildSpecificDeserializer(writerSchema, readerSchema), executor)
.thenAccept(d -> {
fastSpecificRecordDeserializersCache.put(schemaKey, d);
});
buildFastClassWithNumCheck(
() -> CompletableFuture.supplyAsync(() -> buildSpecificDeserializer(writerSchema, readerSchema), executor)
.thenAccept(s -> {
fastSpecificRecordDeserializersCache.put(schemaKey, s);
}));
}
}

Expand All @@ -234,10 +272,11 @@ public FastDeserializer<?> getFastGenericDeserializer(Schema writerSchema, Schem
new FastDeserializerWithAvroGenericImpl(writerSchema, readerSchema));
if (deserializer == null) {
deserializer = fastGenericRecordDeserializersCache.get(schemaKey);
CompletableFuture.supplyAsync(() -> buildGenericDeserializer(writerSchema, readerSchema), executor)
.thenAccept(d -> {
fastGenericRecordDeserializersCache.put(schemaKey, d);
});
buildFastClassWithNumCheck(
() -> CompletableFuture.supplyAsync(() -> buildGenericDeserializer(writerSchema, readerSchema), executor)
.thenAccept(s -> {
fastGenericRecordDeserializersCache.put(schemaKey, s);
}));
}
}
return deserializer;
Expand All @@ -258,9 +297,11 @@ public FastSerializer<?> getFastSpecificSerializer(Schema schema) {
fastSpecificRecordSerializersCache.putIfAbsent(schemaKey, new FastSerializerWithAvroSpecificImpl(schema));
if (serializer == null) {
serializer = fastSpecificRecordSerializersCache.get(schemaKey);
CompletableFuture.supplyAsync(() -> buildSpecificSerializer(schema), executor).thenAccept(s -> {
fastSpecificRecordSerializersCache.put(schemaKey, s);
});
buildFastClassWithNumCheck(
() -> CompletableFuture.supplyAsync(() -> buildSpecificSerializer(schema), executor)
.thenAccept(s -> {
fastSpecificRecordSerializersCache.put(schemaKey, s);
}));
}
}

Expand All @@ -283,9 +324,11 @@ public FastSerializer<?> getFastGenericSerializer(Schema schema) {
fastGenericRecordSerializersCache.putIfAbsent(schemaKey, new FastSerializerWithAvroGenericImpl(schema));
if (serializer == null) {
serializer = fastGenericRecordSerializersCache.get(schemaKey);
CompletableFuture.supplyAsync(() -> buildGenericSerializer(schema), executor).thenAccept(s -> {
fastGenericRecordSerializersCache.put(schemaKey, s);
});
buildFastClassWithNumCheck(
() -> CompletableFuture.supplyAsync(() -> buildGenericSerializer(schema), executor)
.thenAccept(s -> {
fastGenericRecordSerializersCache.put(schemaKey, s);
}));
}
}
return serializer;
Expand All @@ -296,6 +339,26 @@ private String getSchemaKey(Schema writerSchema, Schema readerSchema) {
Utils.getSchemaFingerprint(readerSchema));
}

/**
* A wrapper function that limits the total number of fast de/serilizer calsses generated
*
* @param runnable The function to build and save fast de/serializer
*/
private void buildFastClassWithNumCheck(Runnable runnable) {
try {
if (this.generatedSerDesNum.incrementAndGet() <= this.generatedFastSerDesLimit) {
runnable.run();
} else if (this.generatedSerDesNum.get() == this.generatedFastSerDesLimit + 1) {
// We still want to print the warning when the limit is hit
LOGGER.warn("Generated fast serdes classes number hits limit {}", this.generatedFastSerDesLimit);
} else {
LOGGER.debug("Generated serdes number {}, with fast serdes limit set to {}", this.generatedSerDesNum.get(), this.generatedFastSerDesLimit);
}
} catch (Exception e) {
LOGGER.error("Fast serdes class generation failed");
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Shall we print out the full error stacktrace here?

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Contributor Author

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The exceptions are handled in other functions. So a stack trace here may not provide any useful information.

}
}

/**
* This function will generate a fast specific deserializer, and it will throw exception if anything wrong happens.
* This function can be used to verify whether current {@link FastSerdeCache} could generate proper fast deserializer.
Expand Down