기계 번역으로 제공되는 번역입니다. 제공된 번역과 원본 영어의 내용이 상충하는 경우에는 영어 버전이 우선합니다.
# AWS Lambda Amazon Neptune의 함수 예제
executor;
private final Random idGenerator = new Random();
public MyHandler() {
this.g = AnonymousTraversalSource
.traversal()
.withRemote(DriverRemoteConnection.using(createCluster()));
this.executor = new CallExecutorBuilder()
.config(createRetryConfig())
.build();
}
@Override
public void handleRequest(InputStream input,
OutputStream output,
Context context) throws IOException {
doQuery(input, output);
}
private void doQuery(InputStream input, OutputStream output) throws IOException {
try {
Map args = new HashMap<>();
args.put("id", idGenerator.nextInt());
String result = query(args);
try (Writer writer = new BufferedWriter(new OutputStreamWriter(output, UTF_8))) {
writer.write(result);
}
} finally {
input.close();
output.close();
}
}
private String query(Map args) {
int id = (int) args.get("id");
@SuppressWarnings("unchecked")
Callable query = () -> g.V(id)
.fold()
.coalesce(
unfold(),
addV("Person").property(T.id, id))
.id().next();
Status status = executor.execute(query);
return status.getResult().toString();
}
private Cluster createCluster() {
Cluster.Builder builder = Cluster.build()
.addContactPoint(System.getenv("NEPTUNE_ENDPOINT"))
.port(Integer.parseInt(System.getenv("NEPTUNE_PORT")))
.enableSsl(true)
.minConnectionPoolSize(1)
.maxConnectionPoolSize(1)
.serializer(Serializers.GRAPHBINARY_V1D0)
.reconnectInterval(2000);
if (Boolean.parseBoolean(getOptionalEnv("USE_IAM", "true"))) {
// The following example uses requestInterceptor(), which was introduced
// in TinkerPop 3.6.6. If you are using a TinkerPop version earlier than
// 3.6.6 (but 3.5.5 or higher), use handshakeInterceptor() instead.
builder.requestInterceptor( r ->
{
NeptuneNettyHttpSigV4Signer sigV4Signer = new NeptuneNettyHttpSigV4Signer(region, DefaultCredentialsProvider.create());
sigV4Signer.signRequest(r);
return r;
}
)
return builder.create();
}
private RetryConfig createRetryConfig() {
return new RetryConfigBuilder().retryOnCustomExceptionLogic(retryLogic())
.withDelayBetweenTries(1000, ChronoUnit.MILLIS)
.withMaxNumberOfTries(5)
.withFixedBackoff()
.build();
}
private Function retryLogic() {
return e -> {
StringWriter stringWriter = new StringWriter();
e.printStackTrace(new PrintWriter(stringWriter));
String message = stringWriter.toString();
// Check for connection issues
if ( message.contains("Timed out while waiting for an available host") ||
message.contains("Timed-out waiting for connection on Host") ||
message.contains("Connection to server is no longer active") ||
message.contains("Connection reset by peer") ||
message.contains("SSLEngine closed already") ||
message.contains("Pool is shutdown") ||
message.contains("ExtendedClosedChannelException") ||
message.contains("Broken pipe")) {
return true;
}
// Concurrent writes can sometimes trigger a ConcurrentModificationException.
// In these circumstances you may want to backoff and retry.
if (message.contains("ConcurrentModificationException")) {
return true;
}
// If the primary fails over to a new instance, existing connections to the old primary will
// throw a ReadOnlyViolationException. You may want to back and retry.
if (message.contains("ReadOnlyViolationException")) {
return true;
}
return false;
};
}
private String getOptionalEnv(String name, String defaultValue) {
String value = System.getenv(name);
if (value != null && value.length() > 0) {
return value;
} else {
return defaultValue;
}
}
}
```
함수에 재연결 로직을 포함하려면 [Java 재연결 샘플](access-graph-gremlin-java-reconnect-example.md)을 참조하세요.
## Amazon Neptune용 JavaScript Lambda 함수 예제