Performance metrics and diagnostic information can be obtained from the C/C++
cass_session_get_metrics(). The resulting
contains several useful metrics for accessing request performance and/or
CassMetrics metrics; /* Get a snapshot of the driver's metrics */ cass_session_get_metrics(session, &metrics);
requests field contains information about request latency and
throughput. All latency times are in microseconds and throughput
numbers are in requests per seconds.
stats field contains information about connections
and backpressure markers. If the number of
available_connections is less than
the number of
total_connections this could mean the number of I/O threads or
number of connections may need to be increased. The same is true for
metrics. It could also mean the Cassandra cluster is unable to handle the
current request load.
errors field contains information about the
occurrence of requests and connection timeouts. Request timeouts occur when
a request fails to get a timely response (default: 12 seconds). Pending request
timeouts occur whens a request waits too long to be serviced by an assigned
host. This can occur when too many requests are in-flight for a single host.
Connection timeouts occur when the process of establishing new connections is
unresponsive (default: 5 seconds).