Open Stack

Hi,

We're trying to evaluate OpenStack Swift and would like to understand the best/optimal settings for a swift cluster with the following hardware:

-          Three dual-socket 24-core Intel Xeon servers with 64GB DRAM

-          5 SSDs for storage cluster

I configured the swift-proxy-server on one server and the storage cluster (i.e. account, container and object servers) on another server with 5 SSDs.
Tweaking the #workers in proxy and object server has some improvement in the GET op/s, but latencies increase as well.
For instance, 3500 ops/s and latency of 18 ms (with 8 proxy workers and 16 object workers) vs 7200 ops/s and latency of 35 ms (with 40 proxy workers and 40 object workers). Please note that it's pretty small workload and it's likely most of the requests are served from memory(filesystem cache).

Couple of questions based on my understanding so far.

1.       Is it advisable to enable HT on proxy server and/or storage servers?

2.       I read that a single proxy-server worker can handle only 1024 simultaneous requests and it's good to assign one worker per CPU core. So, would that mean that theoretically the maximum requests that can be serviced simultaneously is 24,576 (on a 24-core server)? If yes, is there any way to go beyond this number?

3.       Is it okay to run container, account and object servers on the same server? Should they each be assigned separate disks?

4.       What's the optimal #workers for container, account and object servers? Is it equivalent to #CPU cores on the server?

5.       When benchmarking with a particular IO size, should I be modifying chunk sizes for proxy and object servers accordingly?

Highly appreciate any inputs and tuning guidelines/suggestions in this regard.

Thanks,
Sushma

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