Appendix A. Acceptor and Connector Configuration Parameters
The tables below detail some of the available parameters used to configure Netty network connections. Parameters and their values are appended to the URI of the connection string. See Network Connections: Acceptors and Connectors for more information. Each table lists the parameters by name and notes whether they can be used with acceptors or connectors or with both. You can use some parameters, for example, only with acceptors.
All Netty parameters are defined in the class org.apache.activemq.artemis.core.remoting.impl.netty.TransportConstants. Source code is available for download on the customer portal.
| Parameter | Use with… | Description |
|---|---|---|
| batchDelay | Both |
Before writing packets to the acceptor or connector, the broker can be configured to batch up writes for a maximum of |
| connectionsAllowed | Acceptors | Limits the number of connections that the acceptor will allow. When this limit is reached, a DEBUG-level message is issued to the log and the connection is refused. The type of client in use determines what happens when the connection is refused. |
| directDeliver | Both |
When a message arrives on the server and is delivered to waiting consumers, by default, the delivery is done on the same thread as that on which the message arrived. This gives good latency in environments with relatively small messages and a small number of consumers, but at the cost of overall throughput and scalability - especially on multi-core machines. If you want the lowest latency and a possible reduction in throughput then you can use the default value for |
| handshake-timeout | Acceptors | Prevents an unauthorized client to open a large number of connections and keep them open. Because each connection requires a file handle, it consumes resources that are then unavailable to other clients. This timeout limits the amount of time a connection can consume resources without having been authenticated. After the connection is authenticated, you can use resource limit settings to limit resource consumption.
The default value is set to After you edit the timeout value, you must restart the broker. |
| localAddress | Connectors | Specifies which local address the client will use when connecting to the remote address. This is typically used in the Application Server or when running Embedded to control which address is used for outbound connections. If the local-address is not set then the connector will use any local address available. |
| localPort | Connectors | Specifies which local port the client will use when connecting to the remote address. This is typically used in the Application Server or when running Embedded to control which port is used for outbound connections. If the default is used, which is 0, then the connector will let the system pick up an ephemeral port. Valid ports are 0 to 65535 |
| nioRemotingThreads | Both |
When configured to use NIO, the broker will by default use a number of threads equal to three times the number of cores (or hyper-threads) as reported by |
| tcpNoDelay | Both |
If this is |
| tcpReceiveBufferSize | Both |
Determines the size of the TCP receive buffer in bytes. The default value is |
| tcpSendBufferSize | Both |
Determines the size of the TCP send buffer in bytes. The default value is TCP buffer sizes should be tuned according to the bandwidth and latency of your network. In summary TCP send/receive buffer sizes should be calculated as: buffer_size = bandwidth * RTT.
Where bandwidth is in bytes per second and network round trip time (RTT) is in seconds. RTT can be easily measured using the For fast networks you may want to increase the buffer sizes from the defaults. |
| Parameter | Use with… | Description |
|---|---|---|
| httpClientIdleTime | Acceptors | How long a client can be idle before sending an empty HTTP request to keep the connection alive. |
| httpClientIdleScanPeriod | Acceptors | How often, in milliseconds, to scan for idle clients. |
| httpEnabled | Acceptors | No longer required. With single port support the broker will now automatically detect if HTTP is being used and configure itself. |
| httpRequiresSessionId | Both |
If |
| httpResponseTime | Acceptors | How long the server can wait before sending an empty HTTP response to keep the connection alive. |
| httpServerScanPeriod | Acceptors | How often, in milliseconds, to scan for clients needing responses. |
| Parameter | Use with… | Description |
|---|---|---|
| enabledCipherSuites | Both | Comma separated list of cipher suites used for SSL communication. The default value is empty which means the JVM’s default will be used. |
| enabledProtocols | Both | Comma separated list of protocols used for SSL communication. The default value is empty which means the JVM’s default will be used. |
| keyStorePassword | Both | When used on an acceptor this is the password for the server-side keystore.
When used on a connector this is the password for the client-side keystore. This is only relevant for a connector if you are using 2-way SSL (that is, mutual authentication). Although this value can be configured on the server, it is downloaded and used by the client. If the client needs to use a different password from that set on the server then it can override the server-side setting by either using the customary |
| keyStorePath | Both | When used on an acceptor this is the path to the SSL key store on the server which holds the server’s certificates (whether self-signed or signed by an authority).
When used on a connector this is the path to the client-side SSL key store which holds the client certificates. This is only relevant for a connector if you are using 2-way SSL (that is, mutual authentication). Although this value is configured on the server, it is downloaded and used by the client. If the client needs to use a different path from that set on the server then it can override the server-side setting by either using the customary |
| needClientAuth | Acceptors |
Tells a client connecting to this acceptor that 2-way SSL is required. Valid values are |
| sslEnabled | Both |
Must be |
| trustStorePassword | Both | When used on an acceptor this is the password for the server-side trust store. This is only relevant for an acceptor if you are using 2-way SSL (that is, mutual authentication).
When used on a connector this is the password for the client-side truststore. Although this value can be configured on the server, it is downloaded and used by the client. If the client needs to use a different password from that set on the server then it can override the server-side setting by either using the customary |
| trustStorePath | Both | When used on an acceptor this is the path to the server-side SSL key store that holds the keys of all the clients that the server trusts. This is only relevant for an acceptor if you are using 2-way SSL (that is, mutual authentication).
When used on a connector this is the path to the client-side SSL key store which holds the public keys of all the servers that the client trusts. Although this value can be configured on the server, it is downloaded and used by the client. If the client needs to use a different path from that set on the server then it can override the server-side setting by either using the customary |
| verifyHost | Both | When used on an acceptor the CN of the connecting client’s SSL certificate will be compared to its hostname to verify they match. This is useful only for 2-way SSL. When used on a connector the CN of the server’s SSL certificate will be compared to its hostname to verify they match. This is useful for both 1-way and 2-way SSL.
Valid values are |
