Sentinel agents¶

Currently three sentinel agents are available and more are being planned and will be released in the near future.

docker stats agent
system stats agent
logfile agent
inline logging guidelines (for self instrumented code)

In addition, it is very easy to use inline code to directly send your logs into sentinel. All agents are written in Python3 and need pip3 to install all dependencies.

common configuration¶

The agent configuration file is called sentinel-agent.conf. Depending on the type of agent you are executing / configuring, the configuration sections may be different. Here we present the common sections present in every configuration file:

[kafka-endpoint]
endpoint = kafka-endpoint:9092
keySerializer = StringSerializer
valueSerializer = StringSerializer

endpoint - set this to the end point of your kafka cluster associated with sentinel framework

[sentinel]
topic = some-topic-name
seriesName = your-series-name

topic - the kafka topic-name that was allocated to sentinel user for a given monitoring space in sentinel
seriesname - the series that was created within the monitoring space

Unless one is writing their own sentinel agent, there is probably no need to change any other configuration parameters under [kafka-endpoint] or [sentinel] sections. Agent specific configuration parameters are covered in each agents subsection next.

docker stats agent¶

The agent is located in the sentinel-agents/dockerstats/ subdirectory in the downloaded git repository. To install all dependencies please use -

# pip3 install -f requirements.txt

The agent can simply be executed via this command -

$ python3 sentinel-docker-agent.py

system stats agent¶

The agent is located in the sentinel-agents/systemstats/ subdirectory in the downloaded git repository. To install all dependencies please use -

# pip3 install -f requirements.txt

The agent can simply be executed via this command -

$ python3 sentinel-sys-agent.py

logfile agent¶

The agent is located in the sentinel-agents/logparsing/ subdirectory in the downloaded git repository. To install all dependencies please use -

# pip3 install -f requirements.txt

The agent can simply be executed via this command -

$ python3 sentinel-log-agent.py

inline logger guidelines¶

In case you wish to send application metrics and logs explicitly and directly to sentinel, you should basically marshall your data point as JSON value with the following structure -

{
    "agent":"sentinel-internal-log-agent",
    "level":"log-level such as error/debug/info/warn",
    "msg":"log message",
    ...
}

The requirement is that you should send a flat JSON data as shown above. agent field is necessary and it's value MUST be set to sentinel-internal-log-agent, rest all JSON fields can be flexibly named and set as per your application needs.

This data point and subsequent points should be sent using any kafka client with kafka-topic and key set to sentinel topic and series that you should have defined already. Use string serialization to send data into kafka endpoint of sentinel.

It is important that the series signature be set to unixtime:s msgtype:json so that sentinel knows how to properly parse the incoming data stream.