windows_exporter/internal/collector/msmq/AGENTS.md

msmq collector

The collector reads the PDH object MSMQ Queue with pdh.CounterTypeRaw. The object exists only where the Message Queuing feature (MSMQ service) is installed. It is multi-instance. These notes were recorded on Windows Server 2025 (build 26100) with no application queues.

• All four counters are PERF_COUNTER_LARGE_RAWCOUNT and are gauges: the help text says they count messages or bytes that "currently reside" in the queue. Bytes ... counters are bytes.
• Instances: Computer Queues plus one instance per queue, named <computer>\private$\<queue> in lower case. A fresh install already has the internal queues server2025\private$\admin_queue$ and server2025\private$\order_queue$. The collector uses the instance name unchanged as the name label.
• For Computer Queues, Messages/Bytes in Queue is the dead-letter queue and Messages/Bytes in Journal Queue is the computer journal.
• All values were 0 on the recording host.

Counter reference

Recorded on Windows Server 2025 (build 26100). Raw and Base are the first and second values that pdh.CounterTypeRaw returns for the sample instance.

MSMQ Queue

Multi-instance. Instances: Computer Queues, server2025\private$\admin_queue$, server2025\private$\order_queue$. Sample instance: Computer Queues.

Counters the collector reads:

Counter	Type	Raw	Base
Bytes in Journal Queue	PERF_COUNTER_LARGE_RAWCOUNT	0
Bytes in Queue	PERF_COUNTER_LARGE_RAWCOUNT	0
Messages in Journal Queue	PERF_COUNTER_LARGE_RAWCOUNT	0
Messages in Queue	PERF_COUNTER_LARGE_RAWCOUNT	0