# The dpdkstat plugin
+This plugin is optional and only has a specific use case: monitoring DPDK applications
+that don't expose stats in any other way than the DPDK xstats API.
+
**Data Plane Development Kit** (DPDK) is a set of drivers and libraries for fast
-packet processing.
+packet processing. Please note that this plugin is a polling based plugin rather
+than an events based plugin (using it will drive up core utilization on a system).
+
+**PLEASE DO NOT USE THIS PLUGIN FOR OVS-DPDK**. dpdkstat is really for DPDK
+applications that have no other way of exposing stats. For OVS or OVS-with-DPDK the
+Open vSwitch plugins available in collectd 5.8.0 should be used for
+collecting stats and events. In addition the OVS plugin is events based rather
+than polling based and will have a smaller footprint on the system.
## Summary
* The same PCI device configuration should be passed to the primary process as
the secondary process uses the same port indexes as the primary.
* A blacklist / whitelist of NICs isn't supported yet.
+ * Plugin initialization time depends on read interval. It requires 5 read
+ cycles to set up internal buffers and states. During that time no statistics
+ are submitted.
+ * If number of DPDK ports is increased while plugin is running, internal
+ buffers are resized. That requires 3 read cycles and no port statistics
+ are submitted in that time.
## License