Package org.apache.tinkerpop.gremlin.server

Class Settings

  • public class Settings
extends Object
    Server settings as configured by a YAML file.
    Author:
    Stephen Mallette (http://stephen.genoprime.com)

    • Field Detail

      • host

        public String host
        Host to bind the server to. Defaults to localhost.

      • port

        public int port
        Port to bind the server to. Defaults to 8182.

      • threadPoolWorker

        public int threadPoolWorker
        Size of the worker thread pool. Defaults to 1 and should generally not exceed 2 * number of cores. A worker thread performs non-blocking read and write for one or more Channels in a non-blocking mode.

      • useEpollEventLoop

        public boolean useEpollEventLoop
        detect if the OS is linux, then use epoll instead of NIO which causes less GC

      • gremlinPool

        public int gremlinPool
        Size of the Gremlin thread pool. This pool handles Gremlin script execution and other related "long-run" processing. Defaults to a setting of 0 which indicates the value should be set to Runtime#availableProcessors().

      • threadPoolBoss

        public int threadPoolBoss
        Size of the boss thread pool. Defaults to 1 and should likely stay at 1. The bossy thread accepts incoming connections on a port until it is unbound. Once a connection is accepted successfully, the boss thread passes processing to the worker threads.

      • evaluationTimeout

        public long evaluationTimeout
        Time in milliseconds to wait for a request (script or bytecode) to complete execution. Defaults to 30000.

      • resultIterationBatchSize

        public int resultIterationBatchSize
        Number of items in a particular resultset to iterate and serialize prior to pushing the data down the wire to the client.

      • maxInitialLineLength

        public int maxInitialLineLength
        The maximum length of the initial line (e.g. "GET / HTTP/1.0") processed in a request, which essentially controls the maximum length of the submitted URI. This setting ties to the Netty HttpRequestDecoder.

      • maxHeaderSize

        public int maxHeaderSize
        The maximum length of all headers. This setting ties to the Netty HttpRequestDecoder

      • maxChunkSize

        public int maxChunkSize
        The maximum length of the content or each chunk. If the content length exceeds this value, the transfer encoding of the decoded request will be converted to 'chunked' and the content will be split into multiple HttpContents. If the transfer encoding of the HTTP request is 'chunked' already, each chunk will be split into smaller chunks if the length of the chunk exceeds this value.

      • maxContentLength

        public int maxContentLength
        The maximum length of the aggregated content for a message. Works in concert with maxChunkSize where chunked requests are accumulated back into a single message. A request exceeding this size will return a 413 - Request Entity Too Large status code. A response exceeding this size will raise an internal exception.

      • maxAccumulationBufferComponents

        public int maxAccumulationBufferComponents
        Maximum number of request components that can be aggregated for a message.

      • writeBufferHighWaterMark

        public int writeBufferHighWaterMark
        If the number of bytes in the network send buffer exceeds this value then the channel is no longer writeable, accepting no additional writes until buffer is drained and the writeBufferLowWaterMark is met.

      • writeBufferLowWaterMark

        public int writeBufferLowWaterMark
        Once the number of bytes queued in the network send buffer exceeds the high water mark, the channel will not become writeable again until the buffer is drained and it drops below this value.

      • idleConnectionTimeout

        public long idleConnectionTimeout
        Time in milliseconds that the server will allow a channel to not receive requests from a client before it automatically closes. If enabled, the value provided should typically exceed the amount of time given to keepAliveInterval. Note that while this value is to be provided as milliseconds it will resolve to second precision. Set this value to 0 to disable this feature.

      • keepAliveInterval

        public long keepAliveInterval
        Time in milliseconds that the server will allow a channel to not send responses to a client before it sends a "ping" to see if it is still present. If it is present, the client should respond with a "pong" which will thus reset the idleConnectionTimeout and keep the channel open. If enabled, this number should be smaller than the value provided to the idleConnectionTimeout. Note that while this value is to be provided as milliseconds it will resolve to second precision. Set this value to 0 to disable this feature.

      • strictTransactionManagement

        public boolean strictTransactionManagement
        If set to true the aliases option is required on requests and Gremlin Server will use that information to control which Graph instances are transaction managed for that request. If this setting is false (which is the default), specification of aliases is not required and Gremlin Server will simply apply a commit for all graphs. This setting only applies to sessionless requests. With either setting the user is responsible for their own transaction management for in-session requests.

      • channelizer

        public String channelizer
        The full class name of the Channelizer to use in Gremlin Server.

      • graphManager

        public String graphManager
        The full class name of the GraphManager to use in Gremlin Server.

      • maxWorkQueueSize

        public int maxWorkQueueSize
        Maximum size the general processing queue can grow before starting to reject requests. The general processing queue is managed by a thread pool that has its size determined by gremlinPool. All incoming requests will be processed by this thread pool. If the threads are exhausted, the requests will queue to the size specified by this value after which they will begin to reject the requests.

        This value should be taken in account with the maxSessionTaskQueueSize which is related in some respects. A request that starts a new Session is handled by this queue, but additional requests to a created Session will queue separately given that setting per session.

        By default this value is set to 8192.

      • maxSessionTaskQueueSize

        public int maxSessionTaskQueueSize
        Maximum size that an individual Session can queue requests before starting to reject them. Note that this configuration only applies to the UnifiedChannelizer. By default this value is set to 4096.
        See Also:
        maxWorkQueueSize

      • maxParameters

        public int maxParameters
        Maximum number of parameters that can be passed on a request. Larger numbers may impact performance for scripts. The default is 16 and this setting only applies to the UnifiedChannelizer.

      • sessionLifetimeTimeout

        public long sessionLifetimeTimeout
        The time in milliseconds that a UnifiedChannelizer session can exist. This value cannot be extended beyond this value irrespective of the number of requests and their individual timeouts. Requests must complete within this time frame. If this timeout is reached while there is a running evaluation, there will be an attempt to interrupt it which will result in a timeout error to the client. If there are existing requests enqueued for the session when this timeout is reached, those requests will not be executed and will be closed with server errors. Open transactions will be issued a rollback. The default is 10 minutes.

      • useGlobalFunctionCacheForSessions

        public boolean useGlobalFunctionCacheForSessions
        Enable the global function cache for sessions when using the UnifiedChannelizer. This setting is only relevant when useGlobalFunctionCacheForSessions is false. When {@link true} it means that functions created in one request to a session remain available on the next request to that session.

      • useCommonEngineForSessions

        public boolean useCommonEngineForSessions
        When true and using the UnifiedChannelizer the same engine that will be used to server sessionless requests will also be use to serve sessions. The default value of true is recommended as it reduces the amount of object creation required for each session and should generally lead to better performance especially if the expectation is that there will be many sessions being created and destroyed rapidly. Setting this value to false is mostly present to support specific use cases that may require each session having its own engine or to match previous functionality provided by the older channelizers produced prior to 3.5.0.

      • serializers

        public List<Settings.SerializerSettings> serializers
        List of MessageSerializer to configure. If no serializers are specified then default serializers for the most current versions of "application/json" and "application/vnd.gremlin-v1.0+gryo" are applied.

      • enableAuditLog

        public Boolean enableAuditLog
        Enable audit logging of authenticated users and gremlin evaluation requests.

    • Constructor Detail

      • Settings

        public Settings()

    • Method Detail

      • getEvaluationTimeout

        public long getEvaluationTimeout()

      • read

        public static Settings read​(String file)
                     throws Exception
        Read configuration from a file into a new Settings object.
        Parameters:
        file - the location of a Gremlin Server YAML configuration file
        Returns:
        a new Optional object wrapping the created Settings
        Throws:
        Exception

      • createDefaultYamlConstructor

        protected static org.yaml.snakeyaml.constructor.Constructor createDefaultYamlConstructor()
        Creates Constructor which contains all configurations to parse a Gremlin Server YAML configuration file using SnakeYAML.
        Returns:
        a Constructor to parse a Gremlin Server YAML

      • read

        public static Settings read​(InputStream stream)
        Read configuration from a file into a new Settings object.
        Parameters:
        stream - an input stream containing a Gremlin Server YAML configuration
        Returns:
        a new Optional object wrapping the created Settings