opentracing-python-cassandra

Instrumentation tools to enable tracing for cassandra-driver.

pip install cassandra_opentracing

Usage

# set up your tracer
cluster = Cluster()
session = cluster.connect('my_keyspace')
QueryTracing(self.session)

This will automatically trace all your queries (except for BatchStatement, see Known Issues). The default span operation name is execute for all queries. Operation name are meant to be low cardinality and there's a standard tag for the query statement: db.statement.

Using fixed span name

QueryTracing(self.session, span_name='execute')

All the spans will be sent to the tracer with the name execute. Note the query string will still be sent in the tag db.statement.

Using a prefix

QueryTracing(self.session, prefix='Custom')

All the spans will contain a prefix and it will looke like: "Custom: SELECT * FROM..."

Using query string as span name

# set up your tracer
cluster = Cluster()
session = cluster.connect('my_keyspace')
QueryTracing(self.session, use_querystring_as_name=True)

If you query contains parameters, the query will include the %s or ?. The span will be the query string, e.g: SELECT * FROM test_table WHERE name = %s.

When passing use_querystring_as_name, you can still use prefix but any value passed in span_name will be ignored.

Adding more span tags

All you have to is:

cluster = Cluster()
session = cluster.connect('my_keyspace')
QueryTracing(self.session, span_tags={'custom_tag': 'value'})

All queries will contain the custom tags.

Using a custom tracer

You may pass a tracer argument to QueryTracing. If you don't, the default opentracing.tracer will be used.

Tags

All traces will contain the following tags:

OpenTracing standard tags:

• db.type: cassandra
• component: cassandra-driver
• db.instance: The execution keyspace except when the keyspace is overriden on the query string (see Known Issues).
• db.statement: The query string itself.
• consistency_level: If the query specified a consistency level, this tag will be present.
• error: In case of error, this will be set to True and a log will be issued with the error message.

Tags added by this library

• command: This indicates the CQL operation, e.g: SELECT, UPDATE, CREATE KEYSPACE, etc.
• paginated: If the query is pagined, this will be set to True.
• reported_duration: The time taken to execute the query. Note that this time takes into account the network roundtrip as well.

Known Issues

• BatchStatement are yet unsupported as there is no simple way to get the executed query strings.
• Queries that override the keyspace (SELECT * FROM keyspace.table) won't have the overriden keyspace sent to the tracer.