| # 3 Broker |
| |
| ## 3.1 Broker Role |
| Broker Role is ASYNC_MASTER, SYNC_MASTER or SLAVE. If you cannot tolerate message missing, we suggest you deploy SYNC_MASTER and attach a SLAVE to it. If you feel ok about missing, but you want the Broker to be always available, you may deploy ASYNC_MASTER with SLAVE. If you just want to make it easy, you may only need a ASYNC_MASTER without SLAVE. |
| ## 3.2 FlushDiskType |
| ASYNC_FLUSH is recommended, for SYNC_FLUSH is expensive and will cause too much performance loss. If you want reliability, we recommend you use SYNC_MASTER with SLAVE. |
| ## 3.3 Broker Configuration |
| | Parameter name | Default | Description | |
| | -------------------------------- | ----------------------------- | ------------------------------------------------------------ | |
| | listenPort | 10911 | listen port for client | |
| | namesrvAddr | null | name server address | |
| | brokerIP1 | InetAddress for network interface | Should be configured if having multiple addresses | |
| | brokerIP2 | InetAddress for network interface | If configured for the Master broker in the Master/Slave cluster, slave broker will connect to this port for data synchronization | |
| | brokerName | null | broker name | |
| | brokerClusterName | DefaultCluster | this broker belongs to which cluster | |
| | brokerId | 0 | broker id, 0 means master, positive integers mean slave | |
| | storePathCommitLog | $HOME/store/commitlog/ | file path for commit log | |
| | storePathConsumerQueue | $HOME/store/consumequeue/ | file path for consume queue | |
| | mappedFileSizeCommitLog | 1024 * 1024 * 1024(1G) | mapped file size for commit log | |
| | deleteWhen | 04 | When to delete the commitlog which is out of the reserve time | |
| | fileReserverdTime | 72 | The number of hours to keep a commitlog before deleting it | |
| | brokerRole | ASYNC_MASTER | SYNC_MASTER/ASYNC_MASTER/SLAVE | |
| | flushDiskType | ASYNC_FLUSH | {SYNC_FLUSH/ASYNC_FLUSH}. Broker of SYNC_FLUSH mode flushes each message onto disk before acknowledging producer. Broker of ASYNC_FLUSH mode, on the other hand, takes advantage of group-committing, achieving better performance. | |
