Welcome! Log In Create A New Profile

Advanced

Re: Nginx throttling issue?

All files from this thread

File Name File Size   Posted by Date  
image003.jpg 3.2 KB open | download John Melom 03/26/2018 Read message
rawRespScatterplot.png 42.3 KB open | download John Melom 03/26/2018 Read message
March 26, 2018 04:58PM
You’re correct that this is the ddos throttling. The real question is what do you want to do? JMeter with zero think time is an imperfect load generator- this is only one complication. The bigger one is the open/closed model issue. With you design you have back ptesssure from your system under test to your load generator. A jmeter virtual user will only ever issue a request when the prior one completes. Real users are not so well behaved which is why your test results will always be over optimistic with this design.

Better approach us to use a load generator that replicates the desired request distribution without triggering the ddos protection. Wrk2, Tsung, httperf are candidates, as well as the cloud based load generator services. Also see Neil Gunther’s paper on how to combine multiple jmeter instances to replicate real world tragic patterns.

Peter

Sent from my iPhone

> On Mar 26, 2018, at 4:21 PM, John Melom <John.Melom@spok.com> wrote:
>
> Hi,
>
> I am load testing our system using Jmeter as a load generator. We execute a script consisting of an https request executing in a loop. The loop does not contain a think time, since at this point I am not trying to emulate a “real user”. I want to get a quick look at our system capacity.. Load on our system is increased by increasing the number of Jmeter threads executing our script. Each Jmeter thread references different data.
>
> Our system is in AWS with an ELB fronting Nginx, which serves as a reverse proxy for our Docker Swarm application cluster.
>
> At moderate loads, a subset of our https requests start experiencing to a 1 second delay in addition to their normal response time. The delay is not due to resource contention. System utilizations remain low. The response times cluster around 4 values: 0 millilseconds, 50 milliseconds, 1 second, and 1.050 seconds. Right now, I am most interested in understanding and eliminating the 1 second delay that gives the clusters at 1 second and 1.050 seconds.
>
> The attachment shows a response time scatterplot from one of our runs. The x-axis is the number of seconds into the run, the y-axis is the response time in milliseconds. The plotted data shows the response time of requests at the time they occurred in the run.
>
> If I run the test bypassing the ELB and Nginx, this delay does not occur.
> If I bypass the ELB, but include Nginx in the request path, the delay returns.
>
> This leads me to believe the 1 second delay is coming from Nginx.
>
> One possible candidate Nginx DDOS. Since all requests are coming from the same Jmeter system, I expect they share the same originating IP address. I attempted to control DDOS throttling by setting limit_req as shown in the nginx.conf fragment below:
>
> http {
> …
> limit_req_zone $binary_remote_addr zone=perf:20m rate=10000r/s;
> …
> server {
> …
> location /myReq {
> limit_req zone=perf burst=600;
> proxy_pass xxx.xxx.xxx.xxx;
> }
> ….
> }
>
> The thinking behind the values set in this conf file is that my aggregate demand would not exceed 10000 requests per second, so throttling of requests should not occur. If there were short bursts more intense than that, the burst value would buffer these requests.
>
> This tuning did not change my results. I still get the 1 second delay.
>
> Am I implementing this correctly?
> Is there something else I should be trying?
>
> The responses are not large, so I don’t believe limit_req is the answer.
> I have a small number of intense users, so limit_conn does not seem likely to be the answer either.
>
> Thanks,
>
> John Melom
> Performance Test Engineer
> Spōk, Inc.
> +1 (952) 230 5311 Office
> John.Melom@spok.com
>
> <image003.jpg>
>
>
> NOTE: This email message and any attachments are for the sole use of the intended recipient(s) and may contain confidential and/or privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you have received this e-mail in error, please contact the sender by replying to this email, and destroy all copies of the original message and any material included with this email.
> <rawRespScatterplot.png>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx
_______________________________________________
nginx mailing list
nginx@nginx.org
http://mailman.nginx.org/mailman/listinfo/nginx
Subject Author Posted

Nginx throttling issue? Attachments

John Melom March 26, 2018 04:22PM

Re: Nginx throttling issue?

pbooth March 26, 2018 04:58PM

RE: Nginx throttling issue?

John Melom March 27, 2018 09:50AM

Re: Nginx throttling issue?

Maxim Dounin March 27, 2018 07:56AM

RE: Nginx throttling issue?

John Melom March 27, 2018 09:54AM

RE: Nginx throttling issue?

John Melom April 04, 2018 05:22PM

Re: Nginx throttling issue?

pbooth April 05, 2018 12:48AM

Re: Nginx throttling issue?

Richard Stanway via nginx April 06, 2018 01:14PM

Re: Nginx throttling issue?

Maxim Dounin April 09, 2018 09:32AM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 131
Record Number of Users: 8 on April 13, 2023
Record Number of Guests: 500 on July 15, 2024
Powered by nginx      Powered by FreeBSD      PHP Powered      Powered by MariaDB      ipv6 ready