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Deploy Raft Listener for NebulaGraph Storage service

Full-text index data is written to the Elasticsearch cluster asynchronously. The Raft Listener (Listener for short) is a separate process that fetches data from the Storage Service and writes them into the Elasticsearch cluster.


  • You have read and fully understood the restrictions for using full-text indexes.
  • You have prepared one or multiple servers to run one or multiple raft listeners.


  • The Storage Service that you want to run as the Listener must have the same or later release with all the other Nebula Graph services in the cluster.
  • For now, you can only add all Listeners to a graph space once and for all. Trying to add a new Listener to a graph space that already has a Listener will fail. To add all Listeners, set them in one statement.

Deployment process

Step 1: Install the Listener service

The Listener service uses the same binary as the storaged service. However, the configuration files are different and the processes use different ports. You can install NebulaGraph on all servers that need to deploy a Listener, but only the storaged service can be used. For details, see Install NebulaGraph by RPM or DEB Package.

Step 2: Prepare the configuration file for the Listener

In the etc directory, remove the suffix from nebula-storaged-listener.conf.default or nebula-storaged-listener.conf.production to nebula-storaged-listener.conf, and then modify the configuration content.

Most configurations are the same as the configurations of Storage Service. This topic only introduces the differences.

Name Default value Description
daemonize true When set to true, the process is a daemon process.
pid_file pids/ The file that records the process ID.
meta_server_addrs - IP (or hostname) and ports of all Meta services. Multiple Meta services are separated by commas.
local_ip - The local IP (or hostname) of the Listener service. Use real IP addresses instead of domain names or loopback IP addresses such as
port - The listening port of the RPC daemon of the Listener service.
heartbeat_interval_secs 10 The heartbeat interval of the Meta service. The unit is second (s).
listener_path data/listener The WAL directory of the Listener. Only one directory is allowed.
data_path data For compatibility reasons, this parameter can be ignored. Fill in the default value data.
part_man_type memory The type of the part manager. Optional values ​​are memory and meta.
rocksdb_batch_size 4096 The default reserved bytes for batch operations.
rocksdb_block_cache 4 The default block cache size of BlockBasedTable. The unit is Megabyte (MB).
engine_type rocksdb The type of the Storage engine, such as rocksdb, memory, etc.
part_type simple The type of the part, such as simple, consensus, etc.

Step 3: Start Listeners

To initiate the Listener, navigate to the installation path of the desired cluster and execute the following command:

./bin/nebula-storaged --flagfile etc/nebula-storaged-listener.conf

Step 4: Add Listeners to NebulaGraph

Connect to NebulaGraph and run USE <space> to enter the graph space that you want to create full-text indexes for. Then run the following statement to add a Listener into NebulaGraph.

ADD LISTENER ELASTICSEARCH <listener_ip:port> [,<listener_ip:port>, ...]


You must use real IPs for a Listener.

Add all Listeners in one statement completely.


Show Listeners

Run the SHOW LISTENER statement to list all Listeners.


| PartId | Type            | Host                   | Host Status |
| 1      | "ELASTICSEARCH" | """:9789" | "ONLINE"    |
| 2      | "ELASTICSEARCH" | """:9789" | "ONLINE"    |
| 3      | "ELASTICSEARCH" | """:9789" | "ONLINE"    |

Remove Listeners

Run the REMOVE LISTENER ELASTICSEARCH statement to remove all Listeners in a graph space.



Last update: January 30, 2024