Bad performance of nginx with Tomcat vs. Apache with Tomcat

[István]

I see,
well I was able to reach about 50K req/s on a single node with nginx with
tuning linux/tcp stack/nginx and i learned one thing:

measure instead of guess

(and as a side effect: debug instead of guess.)

So, if i were you i would start dstat(dstat -cgilpymn) on that host and see
the different elements of you system, enable debug logging, even stracing
nginx

This is the way I think.

Regards,
Istvan



On Thu, Sep 3, 2009 at 10:51 PM, Chang Song <changsong at me.com> wrote:

>
> Istvan.
> It didn't really matter what config I used.
>
> I tried all combinations of
>
> worker_process (2-512)
> worker_connections (512-16000)
> accept_mutex (on/off)
> tcp_nopush (on/off)
> tcp_nodelay (on/off)
> proxy_buffer* (various sizes)
> and other proxy related parameters you can imagine.
> The one I showed you has the best performance
> The following showed the best performance across the board
>
> worker_process 2;           # since we have 2 core machine
> worker_connections 16000;
> accept_mutex off;
> max_connections 256;        # ey-balancer (tomcat had 512 threads)
> everything else default
>
> Thank you.
>
>
>
> On Sep 3, 2009, at 4:26 PM, István wrote:
>
> I think it would be beneficial to show us your nginx config :)
>
> Regards,
> Istvan
>
> On Thu, Sep 3, 2009 at 5:50 AM, Chang Song <changsong at me.com> wrote:
>
>> Sometime ago, I posted an message about Nginx performance when paired with
>> Tomcat.
>> We recently did extensive in-house testing of various workload against
>> Nginx with Tomcat vs Apache vs Tomcat.
>>
>> Apache wins hands down.
>>
>> Here's the basic setup
>>
>> 1. Nginx (2 proc/8192 connections) -> http/1.0 -> Tomcat (HTTP connector)
>> 2. Apache (512 prefork) -> AJP -> Tomcat (AJP)
>>
>> Both KeepAlive off (we don't use KeepAlive due to L4 switch)
>>
>> The physical server is 2 core Intel Xeon, which is typical web server
>> config here.
>> We have three grinder 3.2 load generators.
>> We tested 4K and 20K Tomcat simple HTML file, 20K simple HTML with
>> intentional 10% 200ms
>> sleep in Tomcat serving (emulate slow DB query), etc.
>>
>> Every single case, Apache wins by at least 10-15%.
>> Throughput and response time.
>> Nginx uses a bit less CPU cycles (10-20%), but it is not able drive Tomcat
>> to 100% CPU.
>>
>> Here's my take on this performance problem.
>>
>> 1. Lack of AJP support, which is an optimized HTTP protocol
>>   First of all, this is a serious bottleneck.
>>
>>   * AJP has much less communication overhead than HTTP
>>
>> 2. Lack of HTTP KeepAlive support for proxy
>>
>>   * Lack of AJP may be compensated with HTTP keepalive support since there
>> are
>>     at least twice the number of TIME_WAIT sockets (connection
>> establishment mean time
>>     is at least twice - three times slower than that of Apache)
>>
>> 3. Lack of connection pooling
>>
>>   * Ey-balancer makes things a bit easier, response times are stable, but
>> still the same
>>     average TPS and response time.
>>
>> 4. There seems to be a huge bug in connection management code
>>
>>   Two mix of transactions: 20K HTML serving and 8K HTML with intentional
>> 200ms delay in Tomcat logic
>>
>>   With Apache, 20K HTML serving took  36 ms on average while 8K HTML took
>> 258 ms
>>   With Nginx,  20K HTML serving took 600 ms on average while 8K HTML took
>> 817 ms
>>
>>   I really cannot explain these difference. Not even TCP connection
>> overhead or lack of AJP.
>>
>> My questions is "should I abandon nginx at this point"?
>> I know nginx is great proxy and static file server but I cannot prove my
>> point with Tomcat over and over again.
>>
>> Thank you
>>
>> Chang
>>
>>
>>
>>
>>
>
>
> --
> the sun shines for all
>
>
>


-- 
the sun shines for all
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