Jetty/Howto/Configure Connectors
Contents
Introduction
Jetty provides several types of connectors that allow you to tailor the server setup to suit your circumstances.
Steps
Types of Connectors
SelectChannelConnector
This connector uses efficient NIO buffers with a non-blocking threading model. Jetty uses Direct NIO buffers, and allocates threads only to connections with requests. Synchronization simulates blocking for the servlet API, and any unflushed content at the end of request handling is written asynchronously. See javadoc.
This connector is best used when there are a many connections that have idle periods.
When used with Continuations, threadless waits are supported. When a filter or servlet calls getEvent on a Continuation, a runtime exception is thrown to allow the thread to exit the current request handling. Jetty catches this exception and does not send a response to the client. Instead Jetty releases the thread and places the Continuation on the timer queue. If the Continuation timeout expires, or its resume method is called, then Jetty again allocates a thread to the request, and the request retries. The limitation of this approach is that request content is not available on the retried request, thus if possible it should be read after the Continuation or saved as a request attribute or as the associated object of the Continuation instance.
SocketConnector
This connector implements a traditional blocking IO and threading model. Jetty uses Normal JRE sockets and allocates a thread per connection. Jetty allocates large buffers to active connections only. You should use this Connector only if NIO is not available. See javadoc.
SslSelectChannelConnector
This is an SSL connector that uses NIO. For more information about its configuration, see SSL Connector Reference. See also javadoc.
SslSocketConnector
This is a blocking IO connector that supports SSL. See javadoc.
Ajp13SocketConnector
This connector implements the AJP13 protocol. See How to Configure Ajp13 for more information, and also take a look at How to Configure mod_proxy for alternatives to using the AJP13 protocol. See also javadoc.
Configuration Options
acceptors | The number of thread dedicated to accepting incoming connections. |
acceptQueueSize | Number of connection requests that can be queued up before the operating system starts to send rejections. |
acceptorPriority | Sets the priority of the acceptor threads relative to the other threads. |
confidentialPort | The port to redirect to if there is a security constraint of CONFIDENTIAL. |
confidentialScheme | https by default |
forwarded | If true use hostHeader or else check the headers for retrieving information from the original request to control what ServletRequest#getServerName() and ServletRequest#getServerPort() and ServletRequest#getRemoteAddr() return. Default is false. See How to Configure mod_proxy. |
forwardedHostHeader | The forwarded Host header to use. Default is X-Forwarded-Host. This value is used only if forwarded is true. |
forwardedServerHeader | The forwarded server name header to use. Default is X-Forwarded-Server. This value is used only if forwarded is true. |
forwardedForHeader | The forwarded for header to use. Default is X-Forwarded-For. This value is used only if forwarded is true. |
hostHeader | Set a forced valued for the Host header to control what ServletRequest#getServerName() and ServletRequest#getServerPort() return. This value is used only if forwarded is true. |
host | The particular interface to listen on. If not set or 0.0.0.0, Jetty listens on port on all interfaces. |
integralPort | The port to redirect to if there is a security constraint of INTEGRAL. |
lowResourcesConnections | Sets the number of connections, which if exceeded places this connector in a low resources state. This is not an exact measure as the connection count is averaged over the select sets. When in a low resources state, different idle timeouts can apply on connections. See lowResourcesMaxIdleTime. |
lowResourcesMaxIdleTime | Sets the period in ms that a connection is allowed to be idle when this there are more than lowResourcesConnections connections. This allows the server to rapidly close idle connections in order to gracefully handle high load situations. |
maxIdleTime | Set the maximum Idle time for a connection, which roughly translates to the Socket.setSoTimeout(int) call, although with NIO implementations other mechanisms may be used to implement the timeout. The max idle time is applied: when waiting for a new request to be received on a connection; when reading the headers and content of a request; when writing the headers and content of a response. Jetty interprets this value as the maximum time between some progress being made on the connection. So if a single byte is read or written, then the timeout (if implemented by Jetty) is reset. However, in many instances, the reading/writing is delegated to the JVM, and the semantic is more strictly enforced as the maximum time a single read/write operation can take. Note that as Jetty supports writes of memory-mapped file buffers, a write may take many 10s of seconds for large content written to a slow device. |
name | The name of the connector. Can be used to make a WebAppContext respond only to requests on the named connector via the WebAppContext.setConnectorNames(String[]) method |
port | The port to listen on. See also host. |
requestBufferSize | Sets the size of the content buffer for receiving requests. These buffers are used only for active connections that have requests with bodies that do not fit within the header buffer (see requestHeaderSize). Default is 8K. |
requestHeaderSize | Sets the size of the buffer for request headers. An idle connection at most has one buffer of this size allocated. Default is 6K. |
responseBufferSize | Sets the size of the content buffer for sending responses. These buffers are used only for active connections that are sending responses with bodies that will not fit within the header buffer. Default is 32K. |
responseHeaderSize | Sets the size of the buffer for response headers. Default is 6K. |
resolveNames | If true, request IP addresses will be resolved to host names. |
reuseAddress | True if the the server socket will be opened in SO_REUSEADDR mode. |
soLingerTime | Sets SO_LINGER on the connection socket. Disabled by default. |
statsOn | If true, enables statistics collection on connections. See Statistics. |
useDirectBuffers | For nio connectors, determines whether direct byte buffers will be used or not. The default is true. |
threadPool | Sets the thread pool instance. By default this is the thread pool set on the org.eclipse.jetty.server.Server instance, and is a org.eclipse.jetty.util.thread.QueuedThreadPool instance. |