Methods and systems for removing expired flow table entries using an extended packet processing pipeline

A network appliance comprising:

• a match action pipeline implemented via a packet processing circuit;
• and
• an extended packet processing pipeline implemented via a pipeline circuit that includes a plurality of extended packet processing pipeline stages,
• wherein the match action pipeline is configured to process a plurality of network traffic flows associated with a plurality of flow table entries in a flow table,
• the extended packet processing pipeline is configured to read the plurality of flow table entries,
• the extended packet processing pipeline is configured to determine that a network traffic flow associated with a one of the plurality of flow table entries is expired or terminated, and
• the network appliance is configured to delete the one of the plurality of flow table entries from the flow table by processing a traffic flow deletion operation after determining that the network traffic flow is expired or terminated,
• wherein
• at least one of the extended packet processing pipeline stages determines that the network traffic flow is expired or terminated, and
• a plurality of shards of the flow table contains the plurality of flow table entries, and the extended packet processing pipeline is configured to concurrently search the plurality of shards.

A network appliance comprising

• a means for storing a plurality of flow table entries;
• a means, implemented by a packet processing circuit, for processing a plurality of network traffic flows associated with the plurality of flow table entries;
• a means, implemented by a pipeline circuit, for determining that a network traffic flow associated with one of the flow table entries is expired or terminated based on the one of the flow table-entries;
• and
• a means for deleting the one of the flow table entries from the means for storing the plurality of flow table entries after determining that the network traffic flow is expired or terminated,
• wherein
• the pipeline circuit includes a plurality of extended packet processing pipeline stages;
• at least one extended packet processing pipeline determines that the network traffic flow is expired or terminated,
• a plurality of shards of a flow table contains the flow table entries, and the pipeline circuit is configured to concurrently search the plurality of shards.