PMDAVALKEY(1)

NAME
pmdavalkey - Valkey database PMDA

DESCRIPTION
pmdavalkey is a Performance Co-Pilot (PCP) Performance Metrics Domain Agent (PMDA) which extracts live performance data from a running Valkey database server.

Valkey is a high-performance data structure server that is a fork of Redis. The pmdavalkey agent connects to a Valkey server using the INFO command to retrieve performance metrics covering server operation, memory usage, client connections, persistence, CPU utilization, and statistics.

CONFIGURATION
pmdavalkey reads an optional configuration file:

    $PCP_PMDAS_DIR/valkey/valkey.conf

This file contains settings for connecting to the Valkey server:

host (127.0.0.1)
    Connect to the Valkey server on the given hostname or IP address.

port (6379)
    Connect to the Valkey server on the given port.

The defaults will result in the PMDA connecting to a Valkey server running on localhost on the standard Valkey port (6379).

The PMDA caches metric values for a short period (2 seconds) to avoid overwhelming the Valkey server with frequent INFO command requests.

INSTALLATION
To install, the following must be done as root:

    # cd $PCP_PMDAS_DIR/valkey
    # ./Install

To uninstall, the following must be done as root:

    # cd $PCP_PMDAS_DIR/valkey
    # ./Remove

pmdavalkey is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed.

METRICS
The Valkey PMDA exports the following metric groups:

valkey.server
    Server information including uptime, process ID, server frequency (hz), and configuration file location.

valkey.clients
    Client connection metrics including number of connected, blocked, tracking, and pub/sub clients.

valkey.memory
    Memory usage metrics including used memory, RSS memory, peak memory usage, fragmentation ratio, overhead, dataset size, total system memory, and configured maximum memory.

valkey.stats
    Command and connection statistics including total commands processed, total connections received, rejected connections, keyspace hits and misses, evicted and expired keys, instantaneous operations per second, and network I/O byte counts.

valkey.cpu
    CPU utilization metrics for both the server process and child processes, in both user and system time.

valkey.persistence
    Persistence-related metrics including RDB save information (changes since last save, last save time, background save status and duration) and AOF enabled status.

FILES

$PCP_PMDAS_DIR/valkey/valkey.conf
    configuration file for the pmdavalkey agent

$PCP_PMDAS_DIR/valkey/Install
    installation script for the pmdavalkey agent

$PCP_PMDAS_DIR/valkey/Remove
    undo installation script for the pmdavalkey agent

$PCP_LOG_DIR/pmcd/valkey.log
    default log file for messages from the pmdavalkey agent

Note that the usual/default value for $PCP_PMDAS_DIR is /var/lib/pcp/pmdas and the default for $PCP_LOG_DIR is /var/log/pcp but these settings are platform dependent.

PCP ENVIRONMENT
Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative configuration file, as described in pcp.conf(5).

SEE ALSO
PCPIntro(1), pmcd(1), valkey-server(1) and https://valkey.io.