Network communication (via Netty)¶
Scenario¶
When Flink runs a job, data transmission and reverse pressure detection between tasks depend on Netty. In certain environments, Netty parameters should be configured.
Configuration Description¶
For advanced optimization, you can modify the following Netty configuration items. The default configuration can meet the requirements of tasks of large-scale clusters with high concurrent throughput.
Parameter | Description | Default Value | Mandatory |
|---|---|---|---|
taskmanager.network.netty.num-arenas | Number of Netty memory blocks. | 1 | No |
taskmanager.network.netty.server.numThreads | Number of Netty server threads | 1 | No |
taskmanager.network.netty.client.numThreads | Number of Netty client threads | 1 | No |
taskmanager.network.netty.client.connectTimeoutSec | Netty client connection timeout duration. Unit: second | 120 | No |
taskmanager.network.netty.sendReceiveBufferSize | Size of Netty sending and receiving buffers. This defaults to the system buffer size (cat /proc/sys/net/ipv4/tcp_[rw]mem) and is 4 MB in modern Linux. Unit: byte | 4096 | No |
taskmanager.network.netty.transport | Netty transport type, either nio or epoll | nio | No |