[ENHANCEMENT]: system available memory add to Prometheus exporter output #5821
Description
In CouchDB logs I see an error message
alarm_handler: {set,{system_memory_high_watermark,[]}}
The Erlang Memory Supervisor generated this error message.
https://www.erlang.org/doc/apps/os_mon/memsup.html
As I understand, this alarm is not exported in the Prometheus format. However, it can be evaluated if the operating system reports available memory.
[root@localhost ~]# curl -s http://127.0.0.1:17986/_node/_local/_prometheus | grep couchdb_erlang_memory_bytes
# HELP couchdb_erlang_memory_bytes size of memory (in bytes) dynamically allocated by the Erlang emulator
# TYPE couchdb_erlang_memory_bytes gauge
couchdb_erlang_memory_bytes{memory_type="total"} 1148480680
couchdb_erlang_memory_bytes{memory_type="processes"} 1061616376
couchdb_erlang_memory_bytes{memory_type="processes_used"} 1061601048
couchdb_erlang_memory_bytes{memory_type="system"} 86864304
couchdb_erlang_memory_bytes{memory_type="atom"} 680161
couchdb_erlang_memory_bytes{memory_type="atom_used"} 653349
couchdb_erlang_memory_bytes{memory_type="binary"} 39886392
couchdb_erlang_memory_bytes{memory_type="code"} 14128415
couchdb_erlang_memory_bytes{memory_type="ets"} 9573328Currently, available system memory is not exported by the Prometheus exporter.
Could you add these metric to the Prometheus exporter output?
Later, this can be used to generate an alarm when 80% of the available memory is used.
Tell us how the new feature should work. Be specific
Add system available memory to the Prometheus exporter output.
Not required. Suggest how to implement the addition or change
No response
Additional Context
No response