Remove system-level statistics from README (#1157)

* Remove system-level statistics from README

According to https://community.jitsi.org/t/proposed-videobridge-stats-removal/20431 the system-level statistics cpu_usage, total_memory and used_memory have been removed.

* Remove system-level statistics from README

According to https://community.jitsi.org/t/proposed-videobridge-stats-removal/20431 the system-level statistics cpu_usage, total_memory and used_memory have been removed.

Author: itrich

doc/rest-colibri.md

@@ -124,8 +124,6 @@ The respective response could look like:
 		200 OK with a JSON object which represents the statistics report.
 <pre>
 {
-    "cpu_usage":"0.03015",
-    "used_memory":3732,
     "rtp_loss":"0",
     "bit_rate_download":"0",
     "audiochannels":0,
@@ -134,7 +132,6 @@ The respective response could look like:
     "participants":0,
     "current_timestamp":"2014-08-14 23:26:14.782",
     "threads":17,
-    "total_memory":4051,
     "videochannels":0
 }</pre>
 		(Make sure <a href="using_statistics.md#configuration">statistics are enabled</a>.)

doc/statistics.md

@@ -3,7 +3,6 @@ Introduction
 **Jitsi Videobridge implements reports for the following statistics (and more):**
 
  * Number of threads used by the JVM.
- * Current CPU and memory usage.
  * Current bitrate, packet rate, and packet loss rate.
  * Current number of audio and video channels, and conferences.
  * Current estimated number of video streams.
@@ -22,9 +21,6 @@ Implementation
  * **current_timestamp** - The value is the date and time when the statistics are
 generated (in UTC).
  * **threads** - The number of Java threads that the video bridge is using.
- * **used_memory** - Total used memory on the machine (i.e. what 'free' would return) in megabytes (10^6 B).
- * **total_memory** - The total memory of the machine in megabytes.
- * **cpu_usage** - CPU usage for the machine. The value is between 0 and 1 and is the fraction of the last interval that the CPU spent in either user, nice, system or iowait state (what would appear in the 'cpu' line in 'top').
  * **bit_rate_download / bit_rate_upload** - the total incoming and outgoing (respectively) bitrate for the video bridge in kilobits per second.
  * **packet_rate_download / packet_rate_upload** - the total incoming and outgoing (respectively) packet rate for the video bridge in packets per second.
  * **loss_rate_download** - The fraction of lost incoming RTP packets. This is based on RTP sequence numbers and is relatively accurate.
@@ -57,7 +53,6 @@ The statistics are available through the `/colibri/stats` endpoint on the [priva
   "bit_rate_upload": 0,
   "conference_sizes": [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ],
   "conferences": 0,
-  "cpu_usage": 0.2358490566037736,
   "current_timestamp": "2019-03-14 11:02:15.184",
   "graceful_shutdown": false,
   "jitter_aggregate": 0,
@@ -90,15 +85,13 @@ The statistics are available through the `/colibri/stats` endpoint on the [priva
   "total_loss_controlled_participant_seconds": 847,
   "total_loss_degraded_participant_seconds": 1,
   "total_loss_limited_participant_seconds": 0,
-  "total_memory": 8257,
   "total_packets_dropped_octo": 0,
   "total_packets_received": 266644,
   "total_packets_received_octo": 0,
   "total_packets_sent": 266556,
   "total_packets_sent_octo": 0,
   "total_partially_failed_conferences": 0,
   "total_participants": 2,
-  "used_memory": 4404,
   "videochannels": 0,
   "videostreams": 0
 }
@@ -109,12 +102,9 @@ The statistics can also be published periodically via XMPP (which allows jicofo
 <stats xmlns=' http://jitsi.org/protocol/colibri'>
 	<stat value='2014-07-30 10:13:11.595' name='current_timestamp'/>
 	<stat value='229' name='threads'/>
-	<stat value='702' name='used_memory'/>
-	<stat value='0.1506' name='cpu_usage'/>
 	<stat value='689.0096' name='bit_rate_download'/>
 	<stat value='0.00299' name='rtp_loss'/>
 	<stat value='4' name='audiochannels'/>
-	<stat value='1042' name='total_memory'/>
 	<stat value='700.9024' name='bit_rate_upload'/>
 	<stat value='2' name='conferences'/>
 	<stat value='4' name='videochannels'/>