Symptom:
A few recording errors occur, with CLOSED_ERROR state

Conditions:
This can happen intermittently under a medium to heavy recording load

The Admin CLI command "show tech call_control_service detailed"
will show that the number of audio, plus the number of available_audio_recorders is less than the max_audio_recorders.  For example:

<OraCounter>
       <Counter>Recording</Counter>
       <audio>217</audio>
       <video_low>0</video_low>
       <video_mid>0</video_mid>
       <video_high>0</video_high>
       <max_audio_recorders>572</max_audio_recorders>
       <available_audio_recorders>5</available_audio_recorders>
       <max_video_recorders>72</max_video_recorders>
       <available_video_recorders>72</available_video_recorders>
</OraCounter>