RocksDB statistics

NebulaGraph uses RocksDB as the underlying storage. This topic describes how to collect and show the RocksDB statistics of NebulaGraph.

Enable RocksDB

By default, the function of RocksDB statistics is disabled. To enable RocksDB statistics, you need to:

1. Modify the --enable_rocksdb_statistics parameter as true in the nebula-storaged.conf file. The default path of the configuration file is /use/local/nebula/etc.

2. Restart the service to make the modification valid.

Get RocksDB statistics

Users can use the built-in HTTP service in the storage service to get the following types of statistics. Results in the JSON format are supported.

• All RocksDB statistics.
• Specified RocksDB statistics.

Examples

Use the following command to get all RocksDB statistics:

curl -L "http://${storage_ip}:${port}/rocksdb_stats"

For example:

curl -L "http://172.28.2.1:19779/rocksdb_stats"

rocksdb.blobdb.blob.file.bytes.read=0
rocksdb.blobdb.blob.file.bytes.written=0
rocksdb.blobdb.blob.file.bytes.synced=0
...

Use the following command to get specified RocksDB statistics:

curl -L "http://${storage_ip}:${port}/rocksdb_stats?stats=${stats_name}"

For example, use the following command to get the information of rocksdb.bytes.read and rocksdb.block.cache.add.

curl -L "http://172.28.2.1:19779/rocksdb_stats?stats=rocksdb.bytes.read,rocksdb.block.cache.add"

rocksdb.block.cache.add=14
rocksdb.bytes.read=1632

Use the following command to get specified RocksDB statistics in the JSON format:

curl -L "http://${storage_ip}:${port}/rocksdb_stats?stats=${stats_name}&format=json"

For example, use the following command to get the information of rocksdb.bytes.read and rocksdb.block.cache.add and return the results in the JSON format.

curl -L "http://172.28.2.1:19779/rocksdb_stats?stats=rocksdb.bytes.read,rocksdb.block.cache.add&format=json"

[
  {
    "rocksdb.block.cache.add": 1
  },
  {
    "rocksdb.bytes.read": 160
  }
]