Settings (Apache TinkerPop 3.5.3 API)

java.lang.Object
- org.apache.tinkerpop.gremlin.server.Settings

```
public class Settings
extends Object
```
Server settings as configured by a YAML file.

Author:

Stephen Mallette (http://stephen.genoprime.com)

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Settings.AuthenticationSettings` Settings for the `Authenticator` implementation.
`static class`	`Settings.AuthorizationSettings` Settings for the `Authenticator` implementation.
`static class`	`Settings.BaseMetrics`
`static class`	`Settings.ConsoleReporterMetrics` Settings for a `Metrics` reporter that writes to the console.
`static class`	`Settings.CsvReporterMetrics` Settings for a `Metrics` reporter that writes to a CSV file.
`static class`	`Settings.GangliaReporterMetrics` Settings for a `Metrics` reporter that writes to Ganglia.
`static class`	`Settings.GraphiteReporterMetrics` Settings for a `Metrics` reporter that writes to Graphite.
`static class`	`Settings.HostPortIntervalMetrics`
`static class`	`Settings.IntervalMetrics`
`static class`	`Settings.JmxReporterMetrics` Settings for a `Metrics` reporter that writes to JMX.
`static class`	`Settings.ProcessorSettings` Custom configurations for any `OpProcessor` implementations.
`static class`	`Settings.ScriptEngineSettings` Settings for the `ScriptEngine`.
`static class`	`Settings.SerializerSettings` Settings for the `MessageSerializer` implementations.
`static class`	`Settings.ServerMetrics` Settings for `Metrics` recorded by Gremlin Server.
`static class`	`Settings.Slf4jReporterMetrics` Settings for a `Metrics` reporter that writes to the SL4J output.
`static class`	`Settings.SslSettings` Settings to configure SSL support.

Field Summary

Fields
Modifier and Type	Field and Description
`Settings.AuthenticationSettings`	`authentication`
`Settings.AuthorizationSettings`	`authorization`
`String`	`channelizer` The full class name of the `Channelizer` to use in Gremlin Server.
`Boolean`	`enableAuditLog` Enable audit logging of authenticated users and gremlin evaluation requests.
`long`	`evaluationTimeout` Time in milliseconds to wait for a request (script or bytecode) to complete execution.
`String`	`graphManager` The full class name of the `GraphManager` to use in Gremlin Server.
`Map<String,String>`	`graphs` `Map` of `Graph` objects keyed by their binding name.
`int`	`gremlinPool` Size of the Gremlin thread pool.
`String`	`host` Host to bind the server to.
`long`	`idleConnectionTimeout` Time in milliseconds that the server will allow a channel to not receive requests from a client before it automatically closes.
`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.
`int`	`maxAccumulationBufferComponents` Maximum number of request components that can be aggregated for a message.
`int`	`maxChunkSize` The maximum length of the content or each chunk.
`int`	`maxContentLength` The maximum length of the aggregated content for a message.
`int`	`maxHeaderSize` The maximum length of all headers.
`int`	`maxInitialLineLength` The maximum length of the initial line (e.g.
`int`	`maxParameters` Maximum number of parameters that can be passed on a request.
`int`	`maxSessionTaskQueueSize` Maximum size that an individual `Session` can queue requests before starting to reject them.
`int`	`maxWorkQueueSize` Maximum size the general processing queue can grow before starting to reject requests.
`Settings.ServerMetrics`	`metrics` Configured metrics for Gremlin Server.
`int`	`port` Port to bind the server to.
`List<Settings.ProcessorSettings>`	`processors` Custom settings for `OpProcessor` implementations.
`int`	`resultIterationBatchSize` Number of items in a particular resultset to iterate and serialize prior to pushing the data down the wire to the client.
`Map<String,Settings.ScriptEngineSettings>`	`scriptEngines` `Map` of settings for `ScriptEngine` setting objects keyed by the name of the `ScriptEngine` implementation.
`List<Settings.SerializerSettings>`	`serializers` List of `MessageSerializer` to configure.
`long`	`sessionLifetimeTimeout` The time in milliseconds that a `UnifiedChannelizer` session can exist.
`Settings.SslSettings`	`ssl` Configures settings for SSL.
`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.
`int`	`threadPoolBoss` Size of the boss thread pool.
`int`	`threadPoolWorker` Size of the worker thread pool.
`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.
`boolean`	`useEpollEventLoop` detect if the OS is linux, then use epoll instead of NIO which causes less GC
`boolean`	`useGlobalFunctionCacheForSessions` Enable the global function cache for sessions when using the `UnifiedChannelizer`.
`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.
`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.

Constructor Summary

Constructors
Constructor and Description

Settings()

Constructors
Constructor and Description
`Settings()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected static org.yaml.snakeyaml.constructor.Constructor`	`createDefaultYamlConstructor()` Creates `Constructor` which contains all configurations to parse a Gremlin Server YAML configuration file using SnakeYAML.
`long`	`getEvaluationTimeout()`
`Optional<Settings.ServerMetrics>`	`optionalMetrics()`
`Optional<Settings.ProcessorSettings>`	`optionalProcessor(Class<? extends OpProcessor> clazz)` Find the `Settings.ProcessorSettings` related to the specified class.
`Optional<Settings.SslSettings>`	`optionalSsl()`
`static Settings`	`read(InputStream stream)` Read configuration from a file into a new `Settings` object.
`static Settings`	`read(String file)` Read configuration from a file into a new `Settings` object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 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 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.
  - metrics
```
public Settings.ServerMetrics metrics
```
    Configured metrics for Gremlin Server.
  - graphs
```
public Map<String,String> graphs
```
    Map of Graph objects keyed by their binding name.
  - scriptEngines
```
public Map<String,Settings.ScriptEngineSettings> scriptEngines
```
    Map of settings for ScriptEngine setting objects keyed by the name of the ScriptEngine implementation.
  - 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.
  - ssl
```
public Settings.SslSettings ssl
```
    Configures settings for SSL.
  - authentication
```
public Settings.AuthenticationSettings authentication
```
  - authorization
```
public Settings.AuthorizationSettings authorization
```
  - enableAuditLog
```
public Boolean enableAuditLog
```
    Enable audit logging of authenticated users and gremlin evaluation requests.
  - processors
```
public List<Settings.ProcessorSettings> processors
```
    Custom settings for OpProcessor implementations. Implementations are loaded via ServiceLoader but custom configurations can be supplied through this configuration.
- Constructor Detail
  - Settings
```
public Settings()
```
- Method Detail
  - optionalProcessor
```
public Optional<Settings.ProcessorSettings> optionalProcessor(Class<? extends OpProcessor> clazz)
```
    Find the Settings.ProcessorSettings related to the specified class. If there are multiple entries then only the first is returned.
  - optionalMetrics
```
public Optional<Settings.ServerMetrics> optionalMetrics()
```
  - optionalSsl
```
public Optional<Settings.SslSettings> optionalSsl()
```
  - 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

Class Settings

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

host

port

threadPoolWorker

useEpollEventLoop

gremlinPool

threadPoolBoss

evaluationTimeout

resultIterationBatchSize

maxInitialLineLength

maxHeaderSize

maxChunkSize

maxContentLength

maxAccumulationBufferComponents

writeBufferHighWaterMark

writeBufferLowWaterMark

idleConnectionTimeout

keepAliveInterval

strictTransactionManagement

channelizer

graphManager

maxWorkQueueSize

maxSessionTaskQueueSize

maxParameters

sessionLifetimeTimeout

useGlobalFunctionCacheForSessions

useCommonEngineForSessions

metrics

graphs

scriptEngines

serializers

ssl

authentication

authorization

enableAuditLog

processors

Constructor Detail

Settings

Method Detail

optionalProcessor

optionalMetrics

optionalSsl

getEvaluationTimeout

read

createDefaultYamlConstructor

read