BGP RIB Sharding

The BGP process is split into different threads so that they can run concurrently on a multicore routing engine through RIB sharding which results in reduced convergance time and faster performance. BGP RIB sharding splits a BGP RIB into several sub RIBs and each sub RIB handles a subset of BGP routes. Each sub RIB is served by a separate RPD thread to achieve parallel processing. BGP RIB sharding is disabled by default. This feature is supported only on 64-bit routing protocol process (rpd) where the Routing Engine has at least 4 CPU cores and 16 GB of memory. If you configure rib-sharding on a routing engine, RPD will create sharding threads. By default the number of sharding threads created is same as the number of CPU cores on the routing engine. Optionally, you can specify the number-of-shards you want to create. The range is currently 1 through 31. The show route command shows the aggregate data from main and all shards to provide the unified view of the RIBs. To enable this feature, you can configure rib-sharding at the [edit system processes routing bgp] hierarchy level. Sharding is dependent on the update I/O thread feature. Therefore, update I/O thread feature is essential and mandatory when you configure sharding. To enable update I/O, you need to configure update-threading at the [edit system processes routing bgp] hierarchy level for rib-sharding configuration to pass commit check.