Meta Subsystem

Metanode is the manager of meta partitions and replicated by MultiRaft. Each metanode manages various of partitions. Each partition covers an inode range, and maintains two in-memory btrees: inode btree and dentry btree.

At lease 3 meta nodes are required in respect to high availability.

Properties

Key	Type	Description	Mandatory
role	string	Role of process and must be set to metanode	Yes
listen	string	Listen and accept port of the server	Yes
prof	string	Pprof port	Yes
localIP	string	IP of network to be choose	No. If not specified, the ip address used to communicate with the master is used.
logLevel	string	Level operation for logging. Default is error	No
metadataDir	string	MetaNode store snapshot directory	Yes
logDir	string	Log directory	Yes
raftDir	string	Raft wal directory	Yes
raftHeartbeatPort	string	Raft heartbeat port	Yes
raftReplicaPort	string	Raft replicate port	Yes
consulAddr	string	Addresses of monitor system	No
exporterPort	string	Port for monitor system	No
masterAddr	string	Addresses of master server	Yes
totalMem	string	Max memory metadata used. The value needs to be higher than the value of metaNodeReservedMem in the master configuration. Unit: byte	Yes

Example:

{
     "role": "metanode",
     "listen": "17210",
     "prof": "17220",
     "logLevel": "debug",
     "metadataDir": "/cfs/metanode/data/meta",
     "logDir": "/cfs/metanode/log",
     "raftDir": "/cfs/metanode/data/raft",
     "raftHeartbeatPort": "17230",
     "raftReplicaPort": "17240",
     "consulAddr": "http://consul.prometheus-cfs.local",
     "exporterPort": 9501,
     "totalMem":  "8589934592",
     "masterAddr": [
         "10.196.59.198:17010",
         "10.196.59.199:17010",
         "10.196.59.200:17010"
     ]
 }

Notice

• listen, raftHeartbeatPort, raftReplicaPort can’t be modified after boot startup first time;
• Above config would be stored under directory raftDir in constcfg file. If need modified forcely，you must delete this file manually;
• These configuration items associated with master’s metanode infomation . If they have been modified, master would’t be found old metanode;