add max connections flag (#2037)

docs-2.0/5.configurations-and-logs/1.configurations/3.graph-config.md

@@ -72,6 +72,7 @@ For all parameters and their current values, see [Configurations](1.configuratio
 |`session_idle_timeout_secs` |`28800`               | Specifies the time to expire an idle session. The value ranges from 1 to 604800. The default is 8 hours. This configuration is measured in seconds. |  No|
 |`num_accept_threads`        |`1`               | Specifies the number of threads that accept incoming connections. |  No|
 |`num_netio_threads`         |`0`               | Specifies the number of networking IO threads. `0` is the number of CPU cores. |  No|
+|`num_max_connections`       |`0`              |Max active connections for all networking threads. 0 means no limit.<br/>Max connections for each networking thread = num_max_connections / num_netio_threads|No|
 |`num_worker_threads`        |`0`               | Specifies the number of threads that execute queries. `0` is the number of CPU cores. |  No|
 | `ws_ip`                    | `0.0.0.0`        | Specifies the IP address for the HTTP service. |  No|
 | `ws_http_port`             | `19669`          | Specifies the port for the HTTP service. |  No|

docs-2.0/5.configurations-and-logs/1.configurations/4.storage-config.md

@@ -116,6 +116,7 @@ For all parameters and their current values, see [Configurations](1.configuratio
 | `query_concurrently` |`true`| Whether to turn on multi-threaded queries. Enabling it can improve the latency performance of individual queries, but it will reduce the overall throughput under high pressure. | Yes|
 | `auto_remove_invalid_space` | `true` |After executing `DROP SPACE`, the specified graph space will be deleted. This parameter sets whether to delete all the data in the specified graph space at the same time. When the value is `true`, all the data in the specified graph space will be deleted at the same time.| Yes|
 | `num_io_threads` | `16` | The number of network I/O threads used to send RPC requests and receive responses. | Yes|
+|`num_max_connections`       |`0`              |Max active connections for all networking threads. 0 means no limit.<br/>Max connections for each networking thread = num_max_connections / num_netio_threads|No|
 | `num_worker_threads` | `32` | The number of worker threads for one RPC-based Storage service. | Yes|
 | `max_concurrent_subtasks` | `10` | The maximum number of concurrent subtasks to be executed by the task manager. | Yes|
 | `snapshot_part_rate_limit` | `10485760` | The rate limit when the Raft leader synchronizes the stock data with other members of the Raft group. Unit: bytes/s. | Yes|