in gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/op/AbstractEvalOpProcessor.java [211:350]
protected void evalOpInternal(final Context ctx, final Supplier<GremlinExecutor> gremlinExecutorSupplier,
final BindingSupplier bindingsSupplier) {
final Timer.Context timerContext = evalOpTimer.time();
final RequestMessage msg = ctx.getRequestMessage();
final GremlinExecutor gremlinExecutor = gremlinExecutorSupplier.get();
final GraphManager graphManager = ctx.getGraphManager();
final Settings settings = ctx.getSettings();
final Map<String, Object> args = msg.getArgs();
final String script = (String) args.get(Tokens.ARGS_GREMLIN);
final String language = args.containsKey(Tokens.ARGS_LANGUAGE) ? (String) args.get(Tokens.ARGS_LANGUAGE) : null;
final Bindings bindings = new SimpleBindings();
// sessionless requests are always transaction managed, but in-session requests are configurable.
final boolean managedTransactionsForRequest = manageTransactions ?
true : (Boolean) args.getOrDefault(Tokens.ARGS_MANAGE_TRANSACTION, false);
// timeout override - handle both deprecated and newly named configuration. earlier logic should prevent
// both configurations from being submitted at the same time
final long seto = args.containsKey(Tokens.ARGS_EVAL_TIMEOUT) ?
((Number) args.get(Tokens.ARGS_EVAL_TIMEOUT)).longValue() : settings.getEvaluationTimeout();
final GremlinExecutor.LifeCycle lifeCycle = GremlinExecutor.LifeCycle.build()
.evaluationTimeoutOverride(seto)
.afterFailure((b,t) -> {
graphManager.onQueryError(msg, t);
if (managedTransactionsForRequest) attemptRollback(msg, ctx.getGraphManager(), settings.strictTransactionManagement);
})
.afterTimeout((b, t) -> {
graphManager.onQueryError(msg, t);
})
.beforeEval(b -> {
graphManager.beforeQueryStart(msg);
try {
b.putAll(bindingsSupplier.get());
} catch (OpProcessorException ope) {
// this should bubble up in the GremlinExecutor properly as the RuntimeException will be
// unwrapped and the root cause thrown
throw new RuntimeException(ope);
}
})
.withResult(o -> {
final Iterator itty = IteratorUtils.asIterator(o);
logger.debug("Preparing to iterate results from - {} - in thread [{}]", msg, Thread.currentThread().getName());
if (settings.enableAuditLog) {
AuthenticatedUser user = ctx.getChannelHandlerContext().channel().attr(StateKey.AUTHENTICATED_USER).get();
if (null == user) { // This is expected when using the AllowAllAuthenticator
user = AuthenticatedUser.ANONYMOUS_USER;
}
String address = ctx.getChannelHandlerContext().channel().remoteAddress().toString();
if (address.startsWith("/") && address.length() > 1) address = address.substring(1);
auditLogger.info("User {} with address {} requested: {}", user.getName(), address, script);
}
try {
handleIterator(ctx, itty);
graphManager.onQuerySuccess(msg);
} catch (Exception ex) {
graphManager.onQueryError(msg, ex);
if (managedTransactionsForRequest) attemptRollback(msg, ctx.getGraphManager(), settings.strictTransactionManagement);
CloseableIterator.closeIterator(itty);
// wrap up the exception and rethrow. the error will be written to the client by the evalFuture
// as it will completeExceptionally in the GremlinExecutor
throw new RuntimeException(ex);
}
}).create();
try {
final CompletableFuture<Object> evalFuture = gremlinExecutor.eval(script, language, bindings, lifeCycle);
evalFuture.handle((v, t) -> {
timerContext.stop();
if (t != null) {
// if any exception in the chain is TemporaryException or Failure then we should respond with the
// right error code so that the client knows to retry
final Optional<Throwable> possibleSpecialException = determineIfSpecialException(t);
if (possibleSpecialException.isPresent()) {
final Throwable special = possibleSpecialException.get();
final ResponseMessage.Builder specialResponseMsg = ResponseMessage.build(msg).
statusMessage(special.getMessage()).
statusAttributeException(special);
if (special instanceof TemporaryException) {
specialResponseMsg.code(ResponseStatusCode.SERVER_ERROR_TEMPORARY);
} else if (special instanceof Failure) {
final Failure failure = (Failure) special;
specialResponseMsg.code(ResponseStatusCode.SERVER_ERROR_FAIL_STEP).
statusAttribute(Tokens.STATUS_ATTRIBUTE_FAIL_STEP_MESSAGE, failure.format());
}
ctx.writeAndFlush(specialResponseMsg.create());
} else if (t instanceof OpProcessorException) {
ctx.writeAndFlush(((OpProcessorException) t).getResponseMessage());
} else if (t instanceof TimedInterruptTimeoutException) {
// occurs when the TimedInterruptCustomizerProvider is in play
final String errorMessage = String.format("A timeout occurred within the script during evaluation of [%s] - consider increasing the limit given to TimedInterruptCustomizerProvider", msg);
logger.warn(errorMessage);
ctx.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_TIMEOUT)
.statusMessage("Timeout during script evaluation triggered by TimedInterruptCustomizerProvider")
.statusAttributeException(t).create());
} else if (t instanceof TimeoutException) {
final String errorMessage = String.format("Script evaluation exceeded the configured threshold for request [%s]", msg);
logger.warn(errorMessage, t);
ctx.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_TIMEOUT)
.statusMessage(t.getMessage())
.statusAttributeException(t).create());
} else {
// try to trap the specific jvm error of "Method code too large!" to re-write it as something nicer,
// but only re-write if it's the only error because otherwise we might lose some other important
// information related to the failure. at this point, there hasn't been a scenario that has
// presented itself where the "Method code too large!" comes with other compilation errors so
// it seems that this message trumps other compilation errors to some reasonable degree that ends
// up being favorable for this problem
if (t instanceof MultipleCompilationErrorsException && t.getMessage().contains("Method too large") &&
((MultipleCompilationErrorsException) t).getErrorCollector().getErrorCount() == 1) {
final String errorMessage = String.format("The Gremlin statement that was submitted exceeds the maximum compilation size allowed by the JVM, please split it into multiple smaller statements - %s", trimMessage(msg));
logger.warn(errorMessage);
ctx.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_EVALUATION)
.statusMessage(errorMessage)
.statusAttributeException(t).create());
} else {
final String errorMessage = (t.getMessage() == null) ? t.toString() : t.getMessage();
logger.warn(String.format("Exception processing a script on request [%s].", msg), t);
ctx.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_EVALUATION)
.statusMessage(errorMessage)
.statusAttributeException(t).create());
}
}
}
return null;
});
} catch (RejectedExecutionException ree) {
ctx.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.TOO_MANY_REQUESTS)
.statusMessage("Rate limiting").create());
}
}