# VM Statistics Collector Collects Erlang VM metrics using [:erlang.statistics/1](http://erlang.org/doc/man/erlang.html#statistics-1). ## Exported metrics

```
erlang_vm_statistics_bytes_output_total
```
Type: counter.
The total number of bytes output to ports.
```
erlang_vm_statistics_bytes_received_total
```
Type: counter.
The total number of bytes received through ports.
```
erlang_vm_statistics_context_switches_total
```
Type: counter.
The total number of context switches since the system started.
```
erlang_vm_statistics_garbage_collection_number_of_gcs_total
```
Type: counter.
The total number of garbage collections since the system started.
```
erlang_vm_statistics_garbage_collection_words_reclaimed_total
```
Type: counter.
The total number of words reclaimed by GC since the system started.
```
erlang_vm_statistics_garbage_collection_bytes_reclaimed_total
```
Type: counter.
The total number of bytes reclaimed by GC since the system started.
```
erlang_vm_statistics_reductions_total
```
Type: counter.
Total reductions count.
```
erlang_vm_statistics_run_queues_length_total
```
Type: gauge.
The total length of the run-queues. That is, the number of processes and ports that are ready to run on all available run-queues.
```
erlang_vm_statistics_runtime_seconds_total
```
Type: counter.
The sum of the runtime for all threads in the Erlang runtime system.
```
erlang_vm_statistics_wallclock_time_seconds_total
```
Type: counter.
Can be used in the same manner as erlang_vm_statistics_runtime_seconds_total, except that real time is measured as opposed to runtime or CPU time.

## Configuration Metrics exported by this collector can be configured via `:vm_statistics_collector_metrics` key of `:prometheus` app environment. Options are the same as Item parameter values for [:erlang.statistics/1](http://erlang.org/doc/man/erlang.html#statistics-1): - `:context_switches` for `erlang_vm_statistics_context_switches_total`; - `:garbage_collection` for `erlang_vm_statistics_garbage_collection_number_of_gcs_total`, `:erlang_vm_statistics_garbage_collection_bytes_reclaimed_total`, and `:erlang_vm_statistics_garbage_collection_words_reclaimed_total`; - `:io` for `erlang_vm_statistics_bytes_output_total` and `erlang_vm_statistics_bytes_received_total`; - `:reductions` for `erlang_vm_statistics_reductions_total`; - `:run_queue` for `erlang_vm_statistics_run_queues_length_total`; - `:runtime` for `erlang_vm_statistics_runtime_seconds_total`; - `:wall_clock` for `erlang_vm_statistics_wallclock_time_seconds_total`. By default all metrics are enabled.