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Table 1: Flow-table Scalability Testing Scenarios
Flow-table Scaling Sizing Example
As a reference we give an example on flow-table sizing for a given platform configuration. For example, for the following Skylake platform configuration:
- 1st Level Cache (L1) is 32KB (equivalent to 512 cache line), 2nd Level Cache (L2) is 1MB (equivalent to 16K cache line) and Last Level Cache (LLC) is 322MB (equivalent to 512K cache lines)
- If we assume an IPv4/IPv6 vRouter flow-table, then the entry size is aligned to 2 cache lines
- A small-sized flow-table should be initialized to hold a maximum of 8K entries to fit in local cache (L2). A medium-sized flow-table should be initialized to hold a maximum of 256K entries to fit in Last Level Cache (LLC). A large-sized flow-table should be initialized to hold significantly more than 256K entries to test the case when the table doesn’t fit in cache, hence, a table initialized for 1M entries covers this case.
- For each table size, the table load (i.e. the number of used entries out of total available) will reflect one test case. For example, for a medium sized table of 256K entries, the performance metrics (i.e. lookup rate, insert rate and table utilization) are measured for the case when user inserts 12K entries for the case of an almost-empty flow table, and 128K entries for the half-full case, and 230K entries for the almost-full case. Table -2 summarizes these 9 testing scenarios for the example platform.