Clarification of amount of supported users by Sync Gateway.

[Maxim Letushov]

Hi,

Here is a link to documentation http://developer.couchbase.com/mobile/develop/guides/sync-gateway/deployment/in-production/index.html

In section Sizing and Scaling we can find the next words "Your physical hardware determines how many active, concurrent users you can comfortably support for a single Sync Gateway. A quad-core/4GB RAM backed Sync Gateway can support up to 5k users. Larger boxes, such as a eight-core/8GB RAM backed Sync Gateway, can support 10k users, and so forth."

I need a clarification about words "can support up to 5k users". Is it just the number of sockets that can be stored on 4GB RAM? Is it the number of active parallel operations of reading, writing during replication?

Thanks

[J. Chris Anderson]

Yes this number comes from our performance test where each simulated user has an open continuous sync connection and is receiving documents from all other users, and writing a document occasionally. By using scheduled sync instead of continuous sync, your app will probably use fewer resources per active user, and even for apps that are as resource intensive as our benchmark workload, the 5k reflects the number of users continuously syncing and actively mutating data.

Chris

 

Thanks

[Jens Alfke]

On Jul 20, 2014, at 3:18 AM, Maxim Letushov <maximletush...@gmail.com> wrote:

I need a clarification about words "can support up to 5k users". Is it just the number of sockets that can be stored on 4GB RAM? Is it the number of active parallel operations of reading, writing during replication?

As Chris said, it’s just an estimate, not a hard limit. It’s impossible to give exact numbers because there are so many app- and site-specific variables.

Our QE team put together a test suite that simulates clients performing something resembling a typical workload, and then ran a lot of tests with various numbers of simulated users connecting to various numbers of sync gateways with various sizes of Couchbase Server clusters. Then they graded the tests against various performance metrics, such as the latency of a change pushed by one client being read by another client. From analyzing those we came up with the estimate of about 5,000 users per gateway before performance starts to suffer.

So the bad news is we can’t give exact answers about how many servers you’ll need. But the good news is that both the Sync Gateway and Couchbase Server are very easy to scale (you basically just plug in new nodes) so you can ramp up to meet demand without downtime.

(In the future we may have clearer guidance, as we get more experience with real-world installations. The sales engineers here have a complex Excel spreadsheet that they use for predicting scaling of new Couchbase Server installations, based on past experience. I imagine that something like that will be developed for the Sync Gateway.)

—Jens

[Maxim Letushov]

Thank You

воскресенье, 20 июля 2014 г., 20:47:05 UTC+3 пользователь J. Chris Anderson написал:

[Maxim Letushov]

Thank You

воскресенье, 20 июля 2014 г., 21:32:30 UTC+3 пользователь Jens Alfke написал: