The namespace admin gives you access to several non-standard RPC methods. They will allow you to have fine-grained control over your Klaytn instance, including but not limited to network peer and RPC endpoint management.
admin_nodeInfo
The nodeInfo administrative property can be queried for all the information known about the running Klaytn node at the networking granularity. These include general information about the node itself as a participant of the devp2p P2P overlay protocol, as well as specialized information added by each of the running application protocols, e.g., klay.
The datadir administrative property can be queried for the absolute path the running Klaytn node currently uses to store all its databases. The default path is different depending on the node types (kcn, kpn, and ken) and the OS type.
The peers administrative property can be queried for all the information known about the connected remote nodes at the networking granularity. These include general information about the nodes themselves as participants of the devp2p P2P overlay protocol, as well as specialized information added by each of the running application protocols.
The addPeer is an administrative method that requests adding a new remote node to the list of tracked static nodes. The node will try to maintain connectivity to these nodes at all times, reconnecting every once in a while if the remote connection goes down.
The method accepts a single argument kni, which means "Klaytn Network Identifier". It is similar to the enode concept in the geth. It is URL of the remote peer to start tracking and returns a BOOL indicating whether the peer was accepted for tracking or some error occurred.
Client
Method invocation
Console
admin.addPeer(url)
RPC
{"method": "admin_addPeer", "params": [url]}
Parameters
Name
Type
Description
url
string
Peer's kni URL.
Return Value
Type
Description
bool
true if the peer was accepted, false otherwise.
Example
Console
> admin.addPeer("kni://a979fb575495b8d6db44f750317d0f4622bf4c2aa3365d6af7c284339968eef29b69ad0dce72a4d8db5ebb4968de0e3bec910127f134779fbcb0cb6d3331163c@10.0.0.1:32323") //This is an example address.
true
The removePeer is an administrative method that requests removing a node from the list of tracked static nodes.
The method accepts a single argument kni, which means "Klaytn Network Identifier". It is similar to the enode concept in the geth. It is URL of the remote peer to be removed from a list and returns a BOOL indicating whether the peer was removed or some error occurred.
Client
Method invocation
Console
admin.removePeer(url)
RPC
{"method": "admin_removePeer", "params": [url]}
Parameters
Name
Type
Description
url
string
Peer's kni URL.
Return Value
Type
Description
bool
true if the peer was accepted, false otherwise.
Example
Console
> admin.removePeer("kni://a979fb575495b8d6db44f750317d0f4622bf4c2aa3365d6af7c284339968eef29b69ad0dce72a4d8db5ebb4968de0e3bec910127f134779fbcb0cb6d3331163c@10.0.0.1:32323") //This is an example address.
true
NOTE: This API replaces admin_startRPC. The admin_startRPC will be deprecated soon.
The startHTTP is an administrative method that starts an HTTP based JSON RPC API webserver to handle client requests.
The method returns a boolean flag specifying whether the HTTP RPC listener was opened or not. Please note, only one HTTP endpoint is allowed to be active at any time.
NOTE: This API replaces admin_stopRPC. The admin_stopRPC will be deprecated soon.
The stopHTTP is an administrative method that closes the currently open HTTP RPC endpoint. As the node can only have a single HTTP endpoint running, this method takes no parameters, returning a boolean whether the endpoint was closed or not.
The startWS is an administrative method that starts an WebSocket based JSON RPC API webserver to handle client requests.
The method returns a boolean flag specifying whether the WebSocket RPC listener was opened or not. Please note, only one WebSocket endpoint is allowed to be active at any time.
The stopWS is an administrative method that closes the currently open WebSocket RPC endpoint. As the node can only have a single WebSocket endpoint running, this method takes no parameters, returning a boolean whether the endpoint was closed or not.
The importChain is an administrative method that imports an exported chain from a file into a node. This method imports only blocks that haven't existed in a Klaytn node. This method does not delete any data of the existing chain.
The importChainFromString is an administrative method that imports a chain from a RLP-encoded string of blocks into a Klaytn node. This only works if there is no existing chain in a Klaytn node. This method does not delete any data of the existing chain.
The startStateMigration is an administrative method that starts a state migration and removes old state/storage trie nodes. This can save the storage space of a Klaytn node. The method returns an error if it fails to start a state migration, or null if it succeeds to start. NOTE: After the state migration, the node cannot serve APIs with previous states.
Client
Method invocation
Console
admin.startStateMigration()
RPC
{"method": "admin_startStateMigration"}
Parameters
None
Return Value
Type
Description
Error
null if the state migration has started, or an error message if not.
The stopStateMigration is an administrative method that stops the currently running state migration. This method takes no parameters and returns null or an error whether the state migration was stopped or not.
Client
Method invocation
Console
admin.stopStateMigration()
RPC
{"method": "admin_stopStateMigration"}
Parameters
None
Return Value
Type
Description
Error
null if the state migration is stopped, or an error if not.
The stateMigrationStatus is an administrative method that returns the status information of the state migration. This method takes no parameters and returns the status of the currently running state migration.
Client
Method invocation
Console
admin.stateMigrationStatus
RPC
{"method": "admin_stateMigrationStatus"}
Parameters
None
Return Value
Name
Type
Description
committed
int
committed is the number of trie nodes that have been copied by the state migration.
err
Error
null if the state migration finished well, or an error if not.
isMigration
bool
true if the state migration is running, or false if not.
migrationBlockNumber
uint64
a blockNumber which the state migration started at. (0 if the state migration is not running.)
pending
int
pending represents the number of trie nodes that have not been processed by the state migration.
progress
float64
progress is the progress of the state migration calculated in percent.
read
int
read represents the number of trie nodes that have been read by the state migration.
The saveTrieNodeCacheToDisk is an administrative method that starts saving the cached trie node to the disk to reuse them when the node restarts. Cached trie node data will be stored to and loaded from $DATA_DIR/fastcache . This method returns an error if the saving process has been already triggered or trie node cache is disabled. This feature is supported since Klaytn 1.5.3.
Client
Method invocation
Console
admin.saveTrieNodeCacheToDisk()
RPC
{"method": "admin_saveTrieNodeCacheToDisk"}
Parameters
None
Return Value
Type
Description
Error
null if saving the trie node has started, or an error message if not.
The setMaxSubscriptionPerWSConn is an administrative method that sets the maximum allowed number of subscriptions per single WebSocket connection. For example, if the maximum number is set to five and a user requests more than five subscriptions through the klay_subscribe API, an error message "Maximum 5 subscriptions are allowed for a WebSocket connection" will be displayed. This feature is supported since Klaytn 1.6.0.
Client
Method invocation
Console
admin.setMaxSubscriptionPerWSConn(limit)
RPC
{"method": "admin_setMaxSubscriptionPerWSConn"}
Parameters
Name
Type
Description
limit
int
The maximum allowed number of subscriptions per single WebSocket connection.
Return Value
Type
Description
Error
null if the limit is set successfully; otherwise, it returns an error message.
