Scroll to navigation

CMAP_KEYS(8) Corosync Cluster Engine Programmer's Manual CMAP_KEYS(8)


cmap_keys - Overview of keys stored in the Configuration Map


There are 3 main types of keys stored in CMAP:

* Mapping of values stored in the config file.

* Runtime statistics.

* Other user created values.

In this man page, wild-cards have the usual meaning.


Internal configuration data. All keys in this prefix are read only. It's only useful for getting a list of loaded services.

Values read from the configuration file. It's possible to change them at runtime. If subsystem specific configuration is needed, the key must be in the form logging.logger_subsys.SERVICE.key, where SERVICE is upper case name of the service and key is same as in the configuration file. All values are of string type.

Values read from the configuration file. Each node element in the configuration file gets assigned it's position starting from zero. So the first node from the config file has nodelist.node.0. prefix. To be a valid entry, each node must have ring0_addr key. To change the nodeid key, use a u32 data type.

Local node position is stored in local_node_pos key (RO), so it's easy to find out nodeid/ring addresses of the local node directly from cmap.

Trigger keys for storing fplay data. It's recommended that you the corosync-blackbox command to change keys in this prefix.

There is information about total number of active connections in given moment in the active key, number of closed connections during whole runtime of corosync in the closed key and information about each active IPC connection. All keys in this prefix are read-only.

Each IPC connection has a unique ID. This is in the form [[short_name:][PID:]internal_id. On some platforms, short_name and PID are not filled and only internal_id is used.

Typical keys in this prefix are:

client_pid containing PID of IPC connection (unavailable on some platforms).

dispatched number of dispatched messages.

invalid_request number of requests made by IPC which are invalid (calling non-existing call, ...).

name contains short name of the IPC connection (unavailable on some platforms).

overload is number of requests which were not processed because of overload.

queue_size contains the number of messages in the queue waiting for send.

recv_retries is the total number of interrupted receives.

requests contains the number of requests made by IPC.

responses is the number of responses sent to the IPC client.

send_retries contains the total number of interrupted sends.

service_id contains the ID of service which the IPC is connected to.

Contains the values actually in use by the totem membership protocol. Values here are either taken from the Corosync configuration file, defaults or computed from entries in the config file. For information on individual keys please refer to the man page corosync.conf(5).

Prefix with statistics for service engines. Each service has it's own service_id key in the prefix with the name, where SERVICE is the lower case name of the service. Inside the service prefix is the number of messages received and sent by the corosync engine in the format and, where EXEC_CALL is the internal id of the service call (so for example 3 in cpg service is receive of multicast message from other nodes).

Prefix containing statistics about totem. All keys here are read only. Typical key prefixes:

commit_entered Number of times the processor entered COMMIT state.

commit_token_lost Number of times the processor lost token in COMMIT state.

consensus_timeouts How many times the processor timed out forming a consensus about membership.

continuous_gather How many times the processor was not able to reach consensus.

firewall_enabled_or_nic_failure Set to 1 when processor was not able to reach consensus for long time. The usual reason is a badly configured firewall or connection failure.

gather_entered Number of times the processor entered GATHER state.

gather_token_lost Number of times the processor lost token in GATHER state.

mcast_retx Number of retransmitted messages.

mcast_rx Number of received multicast messages.

mcast_tx Number of transmitted multicast messages.

memb_commit_token_rx Number of received commit tokens.

memb_commit_token_tx Number of transmitted commit tokens.

memb_join_rx Number of received join messages.

memb_join_tx Number of transmitted join messages.

memb_merge_detect_rx Number of received member merge messages.

memb_merge_detect_tx Number of transmitted member merge messages.

orf_token_rx Number of received orf tokens.

orf_token_tx Number of transmitted orf tokens.

recovery_entered Number of times the processor entered recovery.

recovery_token_lost Number of times the token was lost in recovery state.

rx_msg_dropped Number of received messages which were dropped because they were not expected (as example multicast message in commit state).

token_hold_cancel_rx Number of received token hold cancel messages.

token_hold_cancel_tx Number of transmitted token hold cancel messages.

mtt_rx_token Mean transit time of token in milliseconds. In other words, time between two consecutive token receives.

avg_token_workload Average time in milliseconds of holding time of token on the current processor.

avg_backlog_calc Average number of not yet sent messages on the current processor.

Prefix containing members of the totem single ring protocol. Each member keys has format, where key is one of:

ip IP address of member. It's stored in format r(RING_ID) ip(IP_ADDRESS).

join_count Number of times the processor joined membership with local cluster. When processor fails and rejoins again, this value is incremented.

status Status of the processor. Can be one of joined and left.

config_version Config version of the member node.

If corosync is not scheduled after the required period of time it will log this event and also write an entry to cmap under following keys:

timestamp The timestamp of the last time when corosync failed to be scheduled for the required amount of time. The time is milli-seconds since the epoch.

delay The amount of time (milliseconds as a float) that corosync was delayed.

Prefix created by applications using SAM with CMAP integration. It contains the following keys:

recovery Recovery policy of the process. Can be one of quit or restart.

poll_period Value passed in sam_initialize as a time_interval.

last_updated Last time SAM received a heartbeat from the client.

state State of the client. Can be one of failed, stopped, running and waiting for quorum.

Information about users/groups which are allowed to make IPC connections to corosync. Entries loaded from configuration file are stored with uidgid.config.* prefix and are pruned on configuration file reload. Dynamic entries has uidgid.* prefix and a configuration file reload doesn't affect them.

Tells votequorum to cancel waiting for all nodes at cluster startup. Can be used to unblock quorum if notes are known to be down. For pcs use only.

This value will be set to 1 (or created) when a corosync.conf reload is started, and set to 0 when the reload is completed. This allows interested subsystems to do atomic reconfiguration rather than changing each key. Note that individual add/change/delete notifications will still be sent during a reload.

This key is similar to config.totemconfig_reload_in_progress but changed after the totem config trigger is processed. It is useful (mainly) for situations when nodelist.local_node_pos must be correctly reinstated before anything else.


Is the same as in the configuration file. eg: to add UID 500 use

# corosync-cmapctl -s uidgid.uid.500 u8 1

GID is similar, so to add a GID use

# corosync-cmapctl -s uidgid.gid.500 u8 1

For removal of permissions, simply delete the key

# corosync-cmapctl -d uidgid.gid.500


Eg. To add the node with address and nodeid 3. This node is called NEW and it's not running corosync yet.

* Find a node position in the node list which is not used yet. It's recommended that you use highest_number + 1. Let's say output of corosync-cmapctl looks like:

nodelist.local_node_pos (u32) = 1
nodelist.node.0.nodeid (u32) = 1
nodelist.node.0.ring0_addr (str) =
nodelist.node.1.nodeid (u32) = 2
nodelist.node.1.ring0_addr (str) =

So next node position will be 2.

* Add all entries needed for the node on all running nodes, as:

# corosync-cmapctl -s nodelist.node.2.nodeid u32 3
# corosync-cmapctl -s nodelist.node.2.ring0_addr str

Always add the ring0_addr key last. The Corosync engine on all nodes should reply with notice [TOTEM ] adding new UDPU member {} message.

* Add node information to the configuration file on all nodes so that it will survive a restart of corosync.

* Copy and edit configuration file to the NEW node.

* Start corosync on the NEW node.

Removal of a UDPU node is a very similar, slightly reversed action, so

* Stop corosync on the OLD node.

* Remove the relevant entries from cmap on all nodes.

* Change the configuration file on all nodes.


corosync_overview(8), corosync.conf(5), corosync-cmapctl(8)

10/10/2012 corosync Man Page