Stream metrics storage in Influx DB¶

Influx is open source time series DB.

Influx DB installation¶

To install Influx DB on CentOS, do the following:

Create file /etc/yum.repos.d/influxdb.repo:

[influxdb]
name = InfluxDB Repository - RHEL $releasever
baseurl = https://repos.influxdata.com/rhel/$releasever/$basearch/stable
enabled = 1
gpgcheck = 1
gpgkey = https://repos.influxdata.com/influxdb.key

Execute the command
```
yum install influxdb -y
```

Enable UDP connection in /etc/influxdb/influxdb.conf file:

[[udp]]
  enabled = true
  bind-address = ":8089"
  database = "wcs_oam"
  retention-policy = "default"

Start Influx DB
```
systemctl start influxdb
```

The installation procedure for Influx DB on Debian / Ubuntu differs only in the method of adding the necessary repository.

Influx DB can be installed to the same server with monitoring backend server. By default, TCP port 8086 or UDP port 8089 is used to connect to Influx DB.

Influx DB setup¶

To configure Influx DB for metric storage do the following:

Set the following parameter in wcsoam.properties file
```
metric_store=influx
```
Set metrics retention policy in init_tsdb.properties file. By default, metrics are stored for 2 days (48 hours)
```
influx_retention_interval=48h0m0s
```
Launch DB setup script
```
./init_tsdb.sh
```

DB structure¶

The database to store metric values as time series contains fields with the following keys:

VIDEO_HEIGHT
VIDEO_WIDTH
VIDEO_RATE
VIDEO_SYNC
VIDEO_FPS
VIDEO_NACK
VIDEO_PLI
VIDEO_CODEC
AUDIO_SYNC
AUDIO_RATE
AUDIO_LOST
AUDIO_CODEC

Examples of data selection from Influx DB¶

Data can be selected from Influx DB for a stream, for which node and media session identifiers are known:

Enter Influx DB command line interface
```
influx
```
Connect to wcs_oam database
```
use wcs_oam
```

The command

show measurements

will show time series list, every of which corresponds to stream published to certain node in certain media session, for example

name: measurements                                                                         
name                                                                                       
----                                                                                       
3-7ecbd270-123e-11e9-bb40-b96debd59887
3-93412000-123b-11e9-8357-3d4423e30d73

Select video bitrate values for stream on node 3 in media session 7ecbd270-123e-11e9-bb40-b96debd59887
```
select VIDEO_RATE from "3-7ecbd270-123e-11e9-bb40-b96debd59887"
```

Video bitrate values with timestamps will be shown

name: 3-7ecbd270-123e-11e9-bb40-b96debd59887
time                VIDEO_RATE              
----                ----------              
1546839525823000000 28424000                
1546839525960000000 1002914                 
1546839526169000000 727679                  
1546839526358000000 662007                  
1546839526575000000 645467                  
1546839526770000000 633490                  
1546839526967000000 583736                  
1546839527162000000 622472                  
1546839527365000000 593104                  
1546839527563000000 666688                  
1546839527796000000 638784                  
1546839527999000000 637000                  
1546839528192000000 647208                  
1546839528772000000 421640                  
1546839528775000000 587632                  
1546839528805000000 740064                  
1546839529031000000 753504                  
1546839529232000000 767672                  
1546839529431000000 931088                  
1546839529643000000 1090696                 
1546839529840000000 772440                  
1546839530028000000 755744                  
1546839530242000000 812624                  
1546839530429000000 867240                  
1546839530630000000 878008                  
1546839530833000000 873528                  
1546839531031000000 850352                                                                                         
...