| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.tinkerpop.gremlin.server.op.traversal; |
| |
| import com.codahale.metrics.Timer; |
| import com.github.benmanes.caffeine.cache.Cache; |
| import com.github.benmanes.caffeine.cache.Caffeine; |
| import io.netty.channel.ChannelHandlerContext; |
| import org.apache.tinkerpop.gremlin.driver.MessageSerializer; |
| import org.apache.tinkerpop.gremlin.driver.Tokens; |
| import org.apache.tinkerpop.gremlin.driver.message.RequestMessage; |
| import org.apache.tinkerpop.gremlin.driver.message.ResponseMessage; |
| import org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode; |
| import org.apache.tinkerpop.gremlin.jsr223.JavaTranslator; |
| import org.apache.tinkerpop.gremlin.process.traversal.Bytecode; |
| import org.apache.tinkerpop.gremlin.process.traversal.Traversal; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalSideEffects; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.BytecodeHelper; |
| import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalInterruptedException; |
| import org.apache.tinkerpop.gremlin.server.Context; |
| import org.apache.tinkerpop.gremlin.server.GraphManager; |
| import org.apache.tinkerpop.gremlin.server.GremlinServer; |
| import org.apache.tinkerpop.gremlin.server.OpProcessor; |
| import org.apache.tinkerpop.gremlin.server.Settings; |
| import org.apache.tinkerpop.gremlin.server.handler.Frame; |
| import org.apache.tinkerpop.gremlin.server.handler.StateKey; |
| import org.apache.tinkerpop.gremlin.server.op.AbstractOpProcessor; |
| import org.apache.tinkerpop.gremlin.server.op.OpProcessorException; |
| import org.apache.tinkerpop.gremlin.server.util.MetricManager; |
| import org.apache.tinkerpop.gremlin.server.util.SideEffectIterator; |
| import org.apache.tinkerpop.gremlin.server.util.TraverserIterator; |
| import org.apache.tinkerpop.gremlin.structure.Graph; |
| import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONMapper; |
| import org.apache.tinkerpop.gremlin.structure.io.graphson.GraphSONVersion; |
| import org.apache.tinkerpop.gremlin.util.function.ThrowingConsumer; |
| import org.apache.tinkerpop.shaded.jackson.databind.ObjectMapper; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import javax.script.Bindings; |
| import javax.script.ScriptException; |
| import javax.script.SimpleBindings; |
| import java.lang.reflect.UndeclaredThrowableException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.UUID; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.FutureTask; |
| import java.util.concurrent.TimeUnit; |
| |
| import static com.codahale.metrics.MetricRegistry.name; |
| |
| /** |
| * Simple {@link OpProcessor} implementation that iterates remotely submitted serialized {@link Traversal} objects. |
| * |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public class TraversalOpProcessor extends AbstractOpProcessor { |
| private static final Logger logger = LoggerFactory.getLogger(TraversalOpProcessor.class); |
| private static final ObjectMapper mapper = GraphSONMapper.build().version(GraphSONVersion.V2_0).create().createMapper(); |
| public static final String OP_PROCESSOR_NAME = "traversal"; |
| public static final Timer traversalOpTimer = MetricManager.INSTANCE.getTimer(name(GremlinServer.class, "op", "traversal")); |
| |
| public static final Settings.ProcessorSettings DEFAULT_SETTINGS = new Settings.ProcessorSettings(); |
| |
| /** |
| * Configuration setting for how long a cached side-effect will be available before it is evicted from the cache. |
| * |
| * @deprecated As of release 3.3.8, not directly replaced in the protocol as side-effect retrieval after |
| * traversal iteration is not being promoted anymore as a feature. |
| */ |
| @Deprecated |
| public static final String CONFIG_CACHE_EXPIRATION_TIME = "cacheExpirationTime"; |
| |
| /** |
| * Default timeout for a cached side-effect is ten minutes. |
| * |
| * @deprecated As of release 3.3.8, not directly replaced in the protocol as side-effect retrieval after |
| * traversal iteration is not being promoted anymore as a feature. |
| */ |
| @Deprecated |
| public static final long DEFAULT_CACHE_EXPIRATION_TIME = 600000; |
| |
| /** |
| * Configuration setting for the maximum number of entries the cache will have. |
| * |
| * @deprecated As of release 3.3.8, not directly replaced in the protocol as side-effect retrieval after |
| * traversal iteration is not being promoted anymore as a feature. |
| */ |
| @Deprecated |
| public static final String CONFIG_CACHE_MAX_SIZE = "cacheMaxSize"; |
| |
| /** |
| * Default size of the max size of the cache. |
| * |
| * @deprecated As of release 3.3.8, not directly replaced in the protocol as side-effect retrieval after |
| * traversal iteration is not being promoted anymore as a feature. |
| */ |
| @Deprecated |
| public static final long DEFAULT_CACHE_MAX_SIZE = 1000; |
| |
| static { |
| DEFAULT_SETTINGS.className = TraversalOpProcessor.class.getCanonicalName(); |
| DEFAULT_SETTINGS.config = new HashMap<String, Object>() {{ |
| put(CONFIG_CACHE_EXPIRATION_TIME, DEFAULT_CACHE_EXPIRATION_TIME); |
| put(CONFIG_CACHE_MAX_SIZE, DEFAULT_CACHE_MAX_SIZE); |
| }}; |
| } |
| |
| /** |
| * @deprecated As of release 3.3.8, not directly replaced in the protocol as side-effect retrieval after |
| * traversal iteration is not being promoted anymore as a feature. |
| */ |
| protected static Cache<UUID, TraversalSideEffects> cache = null; |
| |
| private static final Bindings EMPTY_BINDINGS = new SimpleBindings(); |
| |
| public TraversalOpProcessor() { |
| super(false); |
| } |
| |
| @Override |
| public String getName() { |
| return OP_PROCESSOR_NAME; |
| } |
| |
| @Override |
| public void close() throws Exception { |
| // do nothing = no resources to release |
| } |
| |
| @Override |
| public void init(final Settings settings) { |
| final Settings.ProcessorSettings processorSettings = settings.processors.stream() |
| .filter(p -> p.className.equals(TraversalOpProcessor.class.getCanonicalName())) |
| .findAny().orElse(TraversalOpProcessor.DEFAULT_SETTINGS); |
| final long maxSize = Long.parseLong(processorSettings.config.get(TraversalOpProcessor.CONFIG_CACHE_MAX_SIZE).toString()); |
| final long expirationTime = Long.parseLong(processorSettings.config.get(TraversalOpProcessor.CONFIG_CACHE_EXPIRATION_TIME).toString()); |
| |
| cache = Caffeine.newBuilder() |
| .expireAfterWrite(expirationTime, TimeUnit.MILLISECONDS) |
| .maximumSize(maxSize) |
| .build(); |
| |
| logger.info("Initialized cache for {} with size {} and expiration time of {} ms", |
| TraversalOpProcessor.class.getSimpleName(), maxSize, expirationTime); |
| } |
| |
| @Override |
| public ThrowingConsumer<Context> select(final Context context) throws OpProcessorException { |
| final RequestMessage message = context.getRequestMessage(); |
| logger.debug("Selecting processor for RequestMessage {}", message); |
| |
| final ThrowingConsumer<Context> op; |
| switch (message.getOp()) { |
| case Tokens.OPS_BYTECODE: |
| validateTraversalSourceAlias(context, message, validateTraversalRequest(message)); |
| op = this::iterateBytecodeTraversal; |
| break; |
| case Tokens.OPS_GATHER: |
| final Optional<String> sideEffectForGather = message.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| if (!sideEffectForGather.isPresent()) { |
| final String msg = String.format("A message with an [%s] op code requires a [%s] argument.", Tokens.OPS_GATHER, Tokens.ARGS_SIDE_EFFECT); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| final Optional<String> sideEffectKey = message.optionalArgs(Tokens.ARGS_SIDE_EFFECT_KEY); |
| if (!sideEffectKey.isPresent()) { |
| final String msg = String.format("A message with an [%s] op code requires a [%s] argument.", Tokens.OPS_GATHER, Tokens.ARGS_SIDE_EFFECT_KEY); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| validateTraversalSourceAlias(context, message, validatedAliases(message).get()); |
| |
| op = this::gatherSideEffect; |
| |
| break; |
| case Tokens.OPS_KEYS: |
| final Optional<String> sideEffectForKeys = message.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| if (!sideEffectForKeys.isPresent()) { |
| final String msg = String.format("A message with an [%s] op code requires a [%s] argument.", Tokens.OPS_GATHER, Tokens.ARGS_SIDE_EFFECT); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| op = varRhc -> { |
| final RequestMessage msg = context.getRequestMessage(); |
| final Optional<UUID> sideEffect = msg.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| final TraversalSideEffects sideEffects = cache.getIfPresent(sideEffect.get()); |
| |
| if (null == sideEffects) |
| logger.warn("Request for side-effect keys on {} returned no side-effects in the cache", sideEffect.get()); |
| |
| handleIterator(varRhc, null == sideEffects ? Collections.emptyIterator() : sideEffects.keys().iterator()); |
| }; |
| |
| break; |
| case Tokens.OPS_CLOSE: |
| final Optional<String> sideEffectForClose = message.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| if (!sideEffectForClose.isPresent()) { |
| final String msg = String.format("A message with an [%s] op code requires a [%s] argument.", Tokens.OPS_CLOSE, Tokens.ARGS_SIDE_EFFECT); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| op = varRhc -> { |
| final RequestMessage msg = context.getRequestMessage(); |
| logger.debug("Close request {} for in thread {}", msg.getRequestId(), Thread.currentThread().getName()); |
| |
| final Optional<UUID> sideEffect = msg.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| cache.invalidate(sideEffect.get()); |
| |
| final String successMessage = String.format("Successfully cleared side effect cache for [%s].", Tokens.ARGS_SIDE_EFFECT); |
| varRhc.writeAndFlush(ResponseMessage.build(message).code(ResponseStatusCode.NO_CONTENT).statusMessage(successMessage).create()); |
| }; |
| |
| break; |
| case Tokens.OPS_INVALID: |
| final String msgInvalid = String.format("Message could not be parsed. Check the format of the request. [%s]", message); |
| throw new OpProcessorException(msgInvalid, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_MALFORMED_REQUEST).statusMessage(msgInvalid).create()); |
| default: |
| final String msgDefault = String.format("Message with op code [%s] is not recognized.", message.getOp()); |
| throw new OpProcessorException(msgDefault, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_MALFORMED_REQUEST).statusMessage(msgDefault).create()); |
| } |
| |
| return op; |
| } |
| |
| private static void validateTraversalSourceAlias(final Context ctx, final RequestMessage message, final Map<String, String> aliases) throws OpProcessorException { |
| final String traversalSourceBindingForAlias = aliases.values().iterator().next(); |
| if (!ctx.getGraphManager().getTraversalSourceNames().contains(traversalSourceBindingForAlias)) { |
| final String msg = String.format("The traversal source [%s] for alias [%s] is not configured on the server.", traversalSourceBindingForAlias, Tokens.VAL_TRAVERSAL_SOURCE_ALIAS); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| } |
| |
| private static Map<String, String> validateTraversalRequest(final RequestMessage message) throws OpProcessorException { |
| if (!message.optionalArgs(Tokens.ARGS_GREMLIN).isPresent()) { |
| final String msg = String.format("A message with [%s] op code requires a [%s] argument.", Tokens.OPS_BYTECODE, Tokens.ARGS_GREMLIN); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| return validatedAliases(message).get(); |
| } |
| |
| private static Optional<Map<String, String>> validatedAliases(final RequestMessage message) throws OpProcessorException { |
| final Optional<Map<String, String>> aliases = message.optionalArgs(Tokens.ARGS_ALIASES); |
| if (!aliases.isPresent()) { |
| final String msg = String.format("A message with [%s] op code requires a [%s] argument.", Tokens.OPS_BYTECODE, Tokens.ARGS_ALIASES); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| if (aliases.get().size() != 1 || !aliases.get().containsKey(Tokens.VAL_TRAVERSAL_SOURCE_ALIAS)) { |
| final String msg = String.format("A message with [%s] op code requires the [%s] argument to be a Map containing one alias assignment named '%s'.", |
| Tokens.OPS_BYTECODE, Tokens.ARGS_ALIASES, Tokens.VAL_TRAVERSAL_SOURCE_ALIAS); |
| throw new OpProcessorException(msg, ResponseMessage.build(message).code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS).statusMessage(msg).create()); |
| } |
| |
| return aliases; |
| } |
| |
| private void gatherSideEffect(final Context context) throws OpProcessorException { |
| final RequestMessage msg = context.getRequestMessage(); |
| logger.debug("Side-effect request {} for in thread {}", msg.getRequestId(), Thread.currentThread().getName()); |
| |
| // earlier validation in selection of this op method should free us to cast this without worry |
| final Optional<UUID> sideEffect = msg.optionalArgs(Tokens.ARGS_SIDE_EFFECT); |
| final Optional<String> sideEffectKey = msg.optionalArgs(Tokens.ARGS_SIDE_EFFECT_KEY); |
| final Map<String, String> aliases = (Map<String, String>) msg.optionalArgs(Tokens.ARGS_ALIASES).get(); |
| |
| final GraphManager graphManager = context.getGraphManager(); |
| final String traversalSourceName = aliases.entrySet().iterator().next().getValue(); |
| final TraversalSource g = graphManager.getTraversalSource(traversalSourceName); |
| |
| final Timer.Context timerContext = traversalOpTimer.time(); |
| try { |
| final ChannelHandlerContext ctx = context.getChannelHandlerContext(); |
| final Graph graph = g.getGraph(); |
| |
| context.getGremlinExecutor().getExecutorService().submit(() -> { |
| try { |
| beforeProcessing(graph, context); |
| |
| try { |
| final TraversalSideEffects sideEffects = cache.getIfPresent(sideEffect.get()); |
| |
| if (null == sideEffects) { |
| final String errorMessage = String.format("Could not find side-effects for %s.", sideEffect.get()); |
| logger.warn(errorMessage); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR).statusMessage(errorMessage).create()); |
| onError(graph, context); |
| return; |
| } |
| |
| if (!sideEffects.exists(sideEffectKey.get())) { |
| final String errorMessage = String.format("Could not find side-effect key for %s in %s.", sideEffectKey.get(), sideEffect.get()); |
| logger.warn(errorMessage); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR).statusMessage(errorMessage).create()); |
| onError(graph, context); |
| return; |
| } |
| |
| handleIterator(context, new SideEffectIterator(sideEffects.get(sideEffectKey.get()), sideEffectKey.get())); |
| } catch (Exception ex) { |
| logger.warn(String.format("Exception processing a side-effect on iteration for request [%s].", msg.getRequestId()), ex); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| onError(graph, context); |
| return; |
| } |
| |
| onSideEffectSuccess(graph, context); |
| } catch (Exception ex) { |
| logger.warn(String.format("Exception processing a side-effect on request [%s].", msg.getRequestId()), ex); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| onError(graph, context); |
| } finally { |
| timerContext.stop(); |
| } |
| }); |
| |
| } catch (Exception ex) { |
| timerContext.stop(); |
| throw new OpProcessorException("Could not iterate the side-effect instance", |
| ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| } |
| } |
| |
| private void iterateBytecodeTraversal(final Context context) throws Exception { |
| final RequestMessage msg = context.getRequestMessage(); |
| logger.debug("Traversal request {} for in thread {}", msg.getRequestId(), Thread.currentThread().getName()); |
| |
| // right now the TraversalOpProcessor can take a direct GraphSON representation of Bytecode or directly take |
| // deserialized Bytecode object. |
| final Object bytecodeObj = msg.getArgs().get(Tokens.ARGS_GREMLIN); |
| final Bytecode bytecode = bytecodeObj instanceof Bytecode ? (Bytecode) bytecodeObj : |
| mapper.readValue(bytecodeObj.toString(), Bytecode.class); |
| |
| // earlier validation in selection of this op method should free us to cast this without worry |
| final Map<String, String> aliases = (Map<String, String>) msg.optionalArgs(Tokens.ARGS_ALIASES).get(); |
| |
| // timeout override - handle both deprecated and newly named configuration. earlier logic should prevent |
| // both configurations from being submitted at the same time |
| final Map<String, Object> args = msg.getArgs(); |
| final long seto = args.containsKey(Tokens.ARGS_SCRIPT_EVAL_TIMEOUT) || args.containsKey(Tokens.ARGS_EVAL_TIMEOUT) |
| // could be sent as an integer or long |
| ? (args.containsKey(Tokens.ARGS_SCRIPT_EVAL_TIMEOUT) ? |
| ((Number) args.get(Tokens.ARGS_SCRIPT_EVAL_TIMEOUT)).longValue() : ((Number) args.get(Tokens.ARGS_EVAL_TIMEOUT)).longValue()) |
| : context.getSettings().getEvaluationTimeout(); |
| |
| final GraphManager graphManager = context.getGraphManager(); |
| final String traversalSourceName = aliases.entrySet().iterator().next().getValue(); |
| final TraversalSource g = graphManager.getTraversalSource(traversalSourceName); |
| |
| final Traversal.Admin<?, ?> traversal; |
| try { |
| final Optional<String> lambdaLanguage = BytecodeHelper.getLambdaLanguage(bytecode); |
| if (!lambdaLanguage.isPresent()) |
| traversal = JavaTranslator.of(g).translate(bytecode); |
| else |
| traversal = context.getGremlinExecutor().eval(bytecode, EMPTY_BINDINGS, lambdaLanguage.get(), traversalSourceName); |
| } catch (ScriptException ex) { |
| logger.error("Traversal contains a lambda that cannot be compiled", ex); |
| throw new OpProcessorException("Traversal contains a lambda that cannot be compiled", |
| ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_SCRIPT_EVALUATION) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| } catch (Exception ex) { |
| logger.error("Could not deserialize the Traversal instance", ex); |
| throw new OpProcessorException("Could not deserialize the Traversal instance", |
| ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_SERIALIZATION) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| } |
| |
| final Timer.Context timerContext = traversalOpTimer.time(); |
| final FutureTask<Void> evalFuture = new FutureTask<>(() -> { |
| final Graph graph = g.getGraph(); |
| |
| try { |
| beforeProcessing(graph, context); |
| |
| try { |
| // compile the traversal - without it getEndStep() has nothing in it |
| traversal.applyStrategies(); |
| handleIterator(context, new TraverserIterator(traversal), graph); |
| } catch (Exception ex) { |
| Throwable t = ex; |
| if (ex instanceof UndeclaredThrowableException) |
| t = t.getCause(); |
| |
| if (t instanceof InterruptedException || t instanceof TraversalInterruptedException) { |
| final String errorMessage = String.format("A timeout occurred during traversal evaluation of [%s] - consider increasing the limit given to evaluationTimeout", msg); |
| logger.warn(errorMessage); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR_TIMEOUT) |
| .statusMessage(errorMessage) |
| .statusAttributeException(ex).create()); |
| onError(graph, context); |
| } else { |
| logger.warn(String.format("Exception processing a Traversal on iteration for request [%s].", msg.getRequestId()), ex); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| onError(graph, context); |
| } |
| } |
| } catch (Exception ex) { |
| logger.warn(String.format("Exception processing a Traversal on request [%s].", msg.getRequestId()), ex); |
| context.writeAndFlush(ResponseMessage.build(msg).code(ResponseStatusCode.SERVER_ERROR) |
| .statusMessage(ex.getMessage()) |
| .statusAttributeException(ex).create()); |
| onError(graph, context); |
| } finally { |
| timerContext.stop(); |
| } |
| |
| return null; |
| }); |
| |
| final Future<?> executionFuture = context.getGremlinExecutor().getExecutorService().submit(evalFuture); |
| if (seto > 0) { |
| // Schedule a timeout in the thread pool for future execution |
| context.getScheduledExecutorService().schedule(() -> executionFuture.cancel(true), seto, TimeUnit.MILLISECONDS); |
| } |
| } |
| |
| @Override |
| protected void iterateComplete(final ChannelHandlerContext ctx, final RequestMessage msg, final Iterator itty) { |
| if (itty instanceof TraverserIterator) { |
| final Traversal.Admin traversal = ((TraverserIterator) itty).getTraversal(); |
| if (!traversal.getSideEffects().isEmpty()) { |
| cache.put(msg.getRequestId(), traversal.getSideEffects()); |
| } |
| } |
| } |
| |
| protected void beforeProcessing(final Graph graph, final Context ctx) { |
| if (graph.features().graph().supportsTransactions() && graph.tx().isOpen()) graph.tx().rollback(); |
| } |
| |
| protected void onError(final Graph graph, final Context ctx) { |
| if (graph.features().graph().supportsTransactions() && graph.tx().isOpen()) graph.tx().rollback(); |
| } |
| |
| protected void onTraversalSuccess(final Graph graph, final Context ctx) { |
| if (graph.features().graph().supportsTransactions() && graph.tx().isOpen()) graph.tx().commit(); |
| } |
| |
| protected void onSideEffectSuccess(final Graph graph, final Context ctx) { |
| // there was no "writing" here, just side-effect retrieval, so if a transaction was opened then |
| // just close with rollback |
| if (graph.features().graph().supportsTransactions() && graph.tx().isOpen()) graph.tx().rollback(); |
| } |
| |
| @Override |
| protected Map<String, Object> generateMetaData(final ChannelHandlerContext ctx, final RequestMessage msg, |
| final ResponseStatusCode code, final Iterator itty) { |
| // leaving this overriding the deprecated version of this method because it provides a decent test to those |
| // who might have their own OpProcessor implementations that apply meta-data. leaving this alone helps validate |
| // that the upgrade path is clean. it can be removed at the next breaking change 3.5.0 |
| Map<String, Object> metaData = Collections.emptyMap(); |
| if (itty instanceof SideEffectIterator) { |
| final SideEffectIterator traversalIterator = (SideEffectIterator) itty; |
| final String key = traversalIterator.getSideEffectKey(); |
| if (key != null) { |
| metaData = new HashMap<>(); |
| metaData.put(Tokens.ARGS_SIDE_EFFECT_KEY, key); |
| metaData.put(Tokens.ARGS_AGGREGATE_TO, traversalIterator.getSideEffectAggregator()); |
| } |
| } else { |
| // this is a standard traversal iterator |
| metaData = super.generateMetaData(ctx, msg, code, itty); |
| } |
| |
| return metaData; |
| } |
| |
| protected void handleIterator(final Context context, final Iterator itty, final Graph graph) throws InterruptedException { |
| final ChannelHandlerContext nettyContext = context.getChannelHandlerContext(); |
| final RequestMessage msg = context.getRequestMessage(); |
| final Settings settings = context.getSettings(); |
| final MessageSerializer serializer = nettyContext.channel().attr(StateKey.SERIALIZER).get(); |
| final boolean useBinary = nettyContext.channel().attr(StateKey.USE_BINARY).get(); |
| boolean warnOnce = false; |
| |
| // we have an empty iterator - happens on stuff like: g.V().iterate() |
| if (!itty.hasNext()) { |
| final Map<String, Object> attributes = generateStatusAttributes(nettyContext, msg, ResponseStatusCode.NO_CONTENT, itty, settings); |
| // if it was a g.V().iterate(), then be sure to add the side-effects to the cache |
| if (itty instanceof TraverserIterator && |
| !((TraverserIterator)itty).getTraversal().getSideEffects().isEmpty()) { |
| cache.put(msg.getRequestId(), ((TraverserIterator)itty).getTraversal().getSideEffects()); |
| } |
| // as there is nothing left to iterate if we are transaction managed then we should execute a |
| // commit here before we send back a NO_CONTENT which implies success |
| onTraversalSuccess(graph, context); |
| context.writeAndFlush(ResponseMessage.build(msg) |
| .code(ResponseStatusCode.NO_CONTENT) |
| .statusAttributes(attributes) |
| .create()); |
| return; |
| } |
| |
| // the batch size can be overridden by the request |
| final int resultIterationBatchSize = (Integer) msg.optionalArgs(Tokens.ARGS_BATCH_SIZE) |
| .orElse(settings.resultIterationBatchSize); |
| List<Object> aggregate = new ArrayList<>(resultIterationBatchSize); |
| |
| // use an external control to manage the loop as opposed to just checking hasNext() in the while. this |
| // prevent situations where auto transactions create a new transaction after calls to commit() withing |
| // the loop on calls to hasNext(). |
| boolean hasMore = itty.hasNext(); |
| |
| while (hasMore) { |
| if (Thread.interrupted()) throw new InterruptedException(); |
| |
| // check if an implementation needs to force flush the aggregated results before the iteration batch |
| // size is reached. |
| final boolean forceFlush = isForceFlushed(nettyContext, msg, itty); |
| |
| // have to check the aggregate size because it is possible that the channel is not writeable (below) |
| // so iterating next() if the message is not written and flushed would bump the aggregate size beyond |
| // the expected resultIterationBatchSize. Total serialization time for the response remains in |
| // effect so if the client is "slow" it may simply timeout. |
| // |
| // there is a need to check hasNext() on the iterator because if the channel is not writeable the |
| // previous pass through the while loop will have next()'d the iterator and if it is "done" then a |
| // NoSuchElementException will raise its head. also need a check to ensure that this iteration doesn't |
| // require a forced flush which can be forced by sub-classes. |
| // |
| // this could be placed inside the isWriteable() portion of the if-then below but it seems better to |
| // allow iteration to continue into a batch if that is possible rather than just doing nothing at all |
| // while waiting for the client to catch up |
| if (aggregate.size() < resultIterationBatchSize && itty.hasNext() && !forceFlush) aggregate.add(itty.next()); |
| |
| // send back a page of results if batch size is met or if it's the end of the results being iterated. |
| // also check writeability of the channel to prevent OOME for slow clients. |
| // |
| // clients might decide to close the Netty channel to the server with a CloseWebsocketFrame after errors |
| // like CorruptedFrameException. On the server, although the channel gets closed, there might be some |
| // executor threads waiting for watermark to clear which will not clear in these cases since client has |
| // already given up on these requests. This leads to these executors waiting for the client to consume |
| // results till the timeout. checking for isActive() should help prevent that. |
| if (nettyContext.channel().isActive() && nettyContext.channel().isWritable()) { |
| if (forceFlush || aggregate.size() == resultIterationBatchSize || !itty.hasNext()) { |
| final ResponseStatusCode code = itty.hasNext() ? ResponseStatusCode.PARTIAL_CONTENT : ResponseStatusCode.SUCCESS; |
| |
| // serialize here because in sessionless requests the serialization must occur in the same |
| // thread as the eval. as eval occurs in the GremlinExecutor there's no way to get back to the |
| // thread that processed the eval of the script so, we have to push serialization down into that |
| final Map<String, Object> metadata = generateResultMetaData(nettyContext, msg, code, itty, settings); |
| final Map<String, Object> statusAttrb = generateStatusAttributes(nettyContext, msg, code, itty, settings); |
| Frame frame = null; |
| try { |
| frame = makeFrame(context, msg, serializer, useBinary, aggregate, code, |
| metadata, statusAttrb); |
| } catch (Exception ex) { |
| // a frame may use a Bytebuf which is a countable release - if it does not get written |
| // downstream it needs to be released here |
| if (frame != null) frame.tryRelease(); |
| |
| // exception is handled in makeFrame() - serialization error gets written back to driver |
| // at that point |
| onError(graph, context); |
| break; |
| } |
| |
| try { |
| // only need to reset the aggregation list if there's more stuff to write |
| if (itty.hasNext()) |
| aggregate = new ArrayList<>(resultIterationBatchSize); |
| else { |
| // iteration and serialization are both complete which means this finished successfully. note that |
| // errors internal to script eval or timeout will rollback given GremlinServer's global configurations. |
| // local errors will get rolledback below because the exceptions aren't thrown in those cases to be |
| // caught by the GremlinExecutor for global rollback logic. this only needs to be committed if |
| // there are no more items to iterate and serialization is complete |
| onTraversalSuccess(graph, context); |
| |
| // exit the result iteration loop as there are no more results left. using this external control |
| // because of the above commit. some graphs may open a new transaction on the call to |
| // hasNext() |
| hasMore = false; |
| } |
| } catch (Exception ex) { |
| // a frame may use a Bytebuf which is a countable release - if it does not get written |
| // downstream it needs to be released here |
| if (frame != null) frame.tryRelease(); |
| throw ex; |
| } |
| |
| if (!itty.hasNext()) iterateComplete(nettyContext, msg, itty); |
| |
| // the flush is called after the commit has potentially occurred. in this way, if a commit was |
| // required then it will be 100% complete before the client receives it. the "frame" at this point |
| // should have completely detached objects from the transaction (i.e. serialization has occurred) |
| // so a new one should not be opened on the flush down the netty pipeline |
| context.writeAndFlush(code, frame); |
| } |
| } else { |
| // don't keep triggering this warning over and over again for the same request |
| if (!warnOnce) { |
| logger.warn("Pausing response writing as writeBufferHighWaterMark exceeded on {} - writing will continue once client has caught up", msg); |
| warnOnce = true; |
| } |
| |
| // since the client is lagging we can hold here for a period of time for the client to catch up. |
| // this isn't blocking the IO thread - just a worker. |
| TimeUnit.MILLISECONDS.sleep(10); |
| } |
| } |
| } |
| } |
