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APM Scalability


I am looking at the F5 APM DataSheet, and I see very impressive numbers for various platforms. What I am wondering is, how do you map these numbers in the real world? As in, if a platfprm calls our support for 10K concurrent users, what sort of traffic pattern are we talking about. One user could have opened multiple applications. For a minute lets assume, 10 applications per user. Does that mean that this platform will be able to scale to the required 10K * 10 = 100K connections?



F5 Employee
F5 Employee
First of all, there's a difference between "concurrent user licensing" and "concurrent access sessions".



Concurrent user licensing is the number of licenses purchased to provide remote connectivity such as SSL VPN, app tunnels, portal access. This does not generally include AAA (authn, authz, acct) functions.



Concurrent access sessions is the total number of sessions that can be maintained on the device per platform. This number includes everything.



When a browser connects to an APM VIP for the first time it is given a session token (cookie) for that session. When the user makes requests, that cookie is relayed to the APM VIP to maintain the application session. The session itself is a record in a table. Concurrent access sessions then is the total amount of table records that a platform can maintain, concurrently. Throughput is not relevant to this equation. One browser with one session cookie equals one session, regardless of throughput requirements. Now, should a user open multiple applications, they could indeed generate new sessions, and it's reasonably a good idea to find a way to "share" the session among the applications (single sign-on, domain cookies, multi-domain configurations, etc.) so that essentially one browser with multiple tabs open will store one session cookie that applies to all (or some) of the open applications.



Kevin made an excellent explanation of licensing, but to answer your direct question - yes, the platform that supports 10k concurrent users can support 100k concurrent connections.