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From Mihai Iacob <mia...@ca.ibm.com>
Subject Re: [PATCH ASF bugzilla# 55897]prefork_mpm patch with SO_REUSEPORT support
Date Fri, 30 May 2014 14:08:50 GMT

how do I unsubsribe from this list ?

Regards,
Mihai Iacob
DB2 Security Development
DB2 pureScale Development
Phone: (905) 413-5378
Email: miacob@ca.ibm.com



From:	Jim Jagielski <jim@jaguNET.com>
To:	dev@httpd.apache.org
Date:	05/30/2014 10:07 AM
Subject:	Re: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
            SO_REUSEPORT support



Thx! Let me review. My plan is to fold into trunk
this weekend.

On May 16, 2014, at 2:53 PM, Lu, Yingqi <yingqi.lu@intel.com> wrote:

> Hi Jim,
>
> Thanks very much for clarifying this with me. I added #ifdef in the code
to check _SC_NPROCESSORS_ONLN in the so_reuseport patch. Bucket patch does
not use this parameter so that it remains the same.
>
> Attached are the two most recent patches. I already updated the bugzilla
#55897 as well.
>
> Thanks,
> Yingqi
>
> -----Original Message-----
> From: Jim Jagielski [mailto:jim@jaguNET.com]
> Sent: Thursday, May 15, 2014 7:53 AM
> To: dev@httpd.apache.org
> Subject: Re: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
SO_REUSEPORT support
>
> I was thinking more about the sysconf(_SC_NPROCESSORS_ONLN) stuff...
> We could either check for that during config/build or protect it with a
#ifdef in the code (and create some logging so the admin nows if it was
found or not).
>
> On May 14, 2014, at 11:59 AM, Lu, Yingqi <yingqi.lu@intel.com> wrote:
>
>> Hi Jim,
>>
>> Thanks very much for your email.
>>
>> In the SO_REUSEPORT patch, SO_REUSEPORT support is checked inside
listen.c file. If the feature is not supported on the OS (for example,
Linux kernel < 3.9), it will fall back to the original behavior.
>>
>> In the bucket patch, there is no need to check the params. With single
listen statement, it is just the default behavior.
>>
>> Please let me know if this answers your question.
>>
>> Thanks,
>> Yingqi
>>
>> -----Original Message-----
>> From: Jim Jagielski [mailto:jim@jaguNET.com]
>> Sent: Wednesday, May 14, 2014 6:57 AM
>> To: dev@httpd.apache.org
>> Subject: Re: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
>> SO_REUSEPORT support
>>
>> This is very cool!
>>
>> mod_status assumes that sysconf() exists, but do we need to do a config
check on the params we use in these patches?
>> We look OK on Linux, FreeBSD and OSX...
>>
>> I'm +1 on folding into trunk.
>>
>> On May 13, 2014, at 7:55 PM, Lu, Yingqi <yingqi.lu@intel.com> wrote:
>>
>>> Dear All,
>>>
>>> During the last couple weeks, I spent some time extending the original
two patches from prefork MPM only to all three Linux MPMs (prefork, worker
and event). Attached is the latest version of the two patches. Bugzilla
database has also been updated already. The ID for the two patches are
#55897 and #56279. Please refer to messages below for details on both of
the patches.
>>>
>>> Quick test result on modern dual socket Intel platform (Linux Kernel
>>> 3.13.9) SO_REUSEPORT patch (bugzilla #55897)
>>> 1.       Prefork MPM: 1 listen statement: 2.16X throughput improvement;
2 listen statements: 2.33X throughput improvement
>>> 2.       Worker MPM: 1 listen statement: 10% throughput improvement; 2
listen statements: 35% throughput improvement
>>> 3.       Event MPM: 1 listen statement: 13% throughput improvement; 2
listen statements: throughput parity, but 62% response time reduction (with
patch, 38% response time as original SW)
>>>
>>> Bucket patch (bugzilla #56279, only impact multiple listen statement
case)
>>> 1.       Prefork MPM: 2 listen statements: 42% throughput improvement
>>> 2.       Worker MPM: 2 listen statements: 7% throughput improvement
>>>
>>> In all the above testing cases, significant response time reductions
are observed, even with throughput improvements.
>>>
>>> Please let me know your feedback and comments.
>>>
>>> Thanks,
>>> Yingqi
>>> Software and workloads used in performance tests may have been
optimized for performance only on Intel microprocessors. Performance tests,
such as SYSmark and MobileMark, are measured using specific computer
systems, components, software, operations and functions. Any change to any
of those factors may cause the results to vary. You should consult other
information and performance tests to assist you in fully evaluating your
contemplated purchases, including the performance of that product when
combined with other products.
>>>
>>> From: Lu, Yingqi [mailto:yingqi.lu@intel.com]
>>> Sent: Monday, March 17, 2014 1:41 PM
>>> To: dev@httpd.apache.org
>>> Subject: RE: FW: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
>>> SO_REUSEPORT support
>>>
>>> Dear all,
>>>
>>> Based on the feedback we received, we modified this patch. Here is the
most recent version. We also modified the Bugzilla database(Bugzilla# 55897
for SO_REUSEPORT patch; Bugzilla# 56279 for bucket patch).
>>>
>>> Below are the changes we made into this new version:
>>>
>>> According to Yann Ylavic and other people's comments, we separate the
original patch between with and without SO_REUSEPORT into two separated
patches. The SO_REUSEPORT patch does not change the original listen
sockets, it just duplicate the original one into multiple ones. Since the
listen sockets are identical, there is no need to change the
idle_server_maintenance function. The bucket patch (without SO_REUSEPORT),
on the other hand, it breaks down the original listen record (if there are
multiple listen socks) to multiple listen record linked lists. In this
case, idle_server_maintenance is implemented at bucket level to address the
situation that imbalanced traffic occurs among different listen
sockets/children buckets. In the bucket patch, the polling in the child
process is removed since each child only listens to 1 sock.
>>>
>>> According to Arkadiusz Miskiewicz's comment, we make the "detection of
SO_REUSEPORT" at run time.
>>>
>>> According to Jeff Trawick's comments, 1. We generate the patches
>>> against the httpd trunk.
>>> 2. We tested the current patches and they do not impact event and
worker mpms. If current patches can be accepted, we would be happy to
extend them to other Linux based mpms. There are not much code changes, but
require some time to setup the workload to test.
>>> 3. We removed unnecessary comments and changed APLOGNO(). We also
changed some of the parameter/variable/function names to better represent
their meanings.
>>> 4. There should be no build-in limitations for SO_REUSEPORT patch. For
bucket patch, the only thing is the number of children bucket only scales
to MAX_SPAWN_RATE. If there are more than 32 (current default
MAX_SPQN_RATE) listen statements specified in the httpd.conf, the number of
buckets will be fixed to 32. The reason for this is because that we
implement the idle_server_maintenance at bucket level, each bucket's own
max_spawn_rate is set to MAX_SPAWN_RATE/num_buckets.
>>>
>>> Again, thanks very much for all the comments and feedback. Please let
us know if there are more changes we need to complete to make them
accepted.
>>>
>>> Thanks,
>>> Yingqi Lu
>>>
>>>
>>>
>>> From: Lu, Yingqi
>>> Sent: Tuesday, March 04, 2014 10:43 AM
>>> To: dev@httpd.apache.org
>>> Subject: RE: FW: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
>>> SO_REUSEPORT support
>>>
>>> Hi Jeff,
>>>
>>> Thanks very much for your time reviewing the patch! We will modify the
patch according to your comments and repost it here.
>>>
>>> Thanks,
>>> Yingqi
>>>
>>> From: Jeff Trawick [mailto:trawick@gmail.com]
>>> Sent: Tuesday, March 04, 2014 10:08 AM
>>> To: Apache HTTP Server Development List
>>> Subject: Re: FW: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
>>> SO_REUSEPORT support
>>>
>>> On Tue, Mar 4, 2014 at 10:35 AM, Lu, Yingqi <yingqi.lu@intel.com>
wrote:
>>> Hi All,
>>>
>>> I just want to ping again on this patch to gather your feedback and
comments. Please refer to the messages below for patch details.
>>>
>>> If you need any additional information/supporting data, please let us
know as well.
>>>
>>> Yeah, it has been on my todo list, but I don't have time to give an
>>> in depth review at the moment.  Here are a few questions/comments.
>>> (And you'll have to deal with the fact that it is unnecessarily
>>> tedious for me to evaluate higher-level considerations if there are a
>>> lot of distractions, such as the code comments below ;)  But others
>>> are of course free to chime in.)
>>>
>>> The patch should be against httpd trunk.  It probably won't take much
time for you to create that patch and confirm basic operation.
>>>
>>> What is the impact to other MPMs, even if they shouldn't use or don't
have the necessary code to use SO_REUSEPORT at this time?
>>>
>>> Have you tried the event MPM?
>>>
>>> Is there a way for the admin to choose this behavior?  Most won't care,
but everyone's behavior is changed AFAICT.
>>>
>>> Are there built-in limitations in this patch that we should be aware
of?  E.g., the free slot/spawn rate changes suggest to me that there can't
be more than 1025 children???
>>>
>>> We should assume for now that there's no reason this couldn't be
committed to trunk after review/rework, so make sure it is as close as you
can get it to what you think is the final form.
>>>
>>> For the configure-time check for 3.9 kernel: I think we'd also use
>>> AC_TRY_COMPILE at configure time to confirm that the SO_REUSEPORT
>>> definition is available, and not enable it if the system includes
>>> doesn't define it.  (Does that cause a problem for any significant
>>> number of people?)
>>>
>>> Don't mention the patch in the patch ;) (e.g., "This function is
>>> added for the patch.")
>>>
>>> Incomplete comments on style/syntax issues:
>>>
>>> * mixing declarations and statements (e.g., "duplr->next = 0;
>>> apr_socket_t *temps;") isn't supported by all compilers and is
>>> distracting when reviewing
>>> * suitable identifier names (e.g., fix global variable "flag" and
>>> whatever else isn't appropriate; "ap_post_config_listeners" should be
>>> renamed to indicate what it does
>>> * APLOGNO(99999) and comments about fixing it: Instead put "APLOGNO()"
>>> and don't add reminders in comments
>>> * this doesn't seem portable: "int free_slots
[MAX_SPAWN_RATE/num_buckets];"
>>> and so on
>>>
>>>
>>> Thanks,
>>> Yingqi
>>>
>>>
>>> From: Lu, Yingqi
>>> Sent: Friday, January 24, 2014 3:26 PM
>>> To: dev@httpd.apache.org
>>> Subject: [PATCH ASF bugzilla# 55897]prefork_mpm patch with
>>> SO_REUSEPORT support
>>>
>>> Dear All,
>>>
>>> Our analysis of Apache httpd 2.4.7 prefork mpm, on 32 and 64 thread
Intel Xeon 2600 series systems, using an open source three tier social
networking web server workload, revealed performance scaling issues.  In
current software single listen statement (listen 80) provides better
scalability due to un-serialized accept. However, when system is under very
high load, this can lead to big number of child processes stuck in D state.
On the other hand, the serialized accept approach cannot scale with the
high load either.  In our analysis, a 32-thread system, with 2 listen
statements specified, could scale to just 70% utilization, and a 64-thread
system, with signal listen statement specified (listen 80, 4 network
interfaces), could scale to only 60% utilization.
>>>
>>> Based on those findings, we created a prototype patch for prefork mpm
which extends performance and thread utilization. In Linux kernel newer
than 3.9, SO_REUSEPORT is enabled. This feature allows multiple sockets
listen to the same IP:port and automatically round robins connections. We
use this feature to create multiple duplicated listener records of the
original one and partition the child processes into buckets. Each bucket
listens to 1 IP:port. In case of old kernel which does not have the
SO_REUSEPORT enabled, we modified the "multiple listen statement case" by
creating 1 listen record for each listen statement and partitioning the
child processes into different buckets. Each bucket listens to 1 IP:port.
>>>
>>> Quick tests of the patch, running the same workload, demonstrated a 22%
throughput increase with 32-threads system and 2 listen statements (Linux
kernel 3.10.4). With the older kernel (Linux Kernel 3.8.8, without
SO_REUSEPORT), 10% performance gain was measured. With single listen
statement (listen 80) configuration, we observed over 2X performance
improvements on modern dual socket Intel platforms (Linux Kernel 3.10.4).
We also observed big reduction in response time, in addition to the
throughput improvement gained in our tests 1.
>>>
>>> Following the feedback from the bugzilla website where we originally
submitted the patch, we removed the dependency of APR change to simplify
the patch testing process. Thanks Jeff Trawick for his good suggestion! We
are also actively working on extending the patch to worker and event MPMs,
as a next step. Meanwhile, we would like to gather comments from all of you
on the current prefork patch. Please take some time test it and let us know
how it works in your environment.
>>>
>>> This is our first patch to the Apache community. Please help us review
it and let us know if there is anything we might revise to improve it. Your
feedback is very much appreciated.
>>>
>>> Configuration:
>>> <IfModule prefork.c>
>>>   ListenBacklog 105384
>>>   ServerLimit 105000
>>>   MaxClients 1024
>>>   MaxRequestsPerChild 0
>>>   StartServers 64
>>>   MinSpareServers 8
>>>   MaxSpareServers 16
>>> </IfModule>
>>>
>>> 1. Software and workloads used in performance tests may have been
optimized for performance only on Intel microprocessors. Performance tests,
such as SYSmark and MobileMark, are measured using specific computer
systems, components, software, operations and functions. Any change to any
of those factors may cause the results to vary. You should consult other
information and performance tests to assist you in fully evaluating your
contemplated purchases, including the performance of that product when
combined with other products.
>>>
>>> Thanks,
>>> Yingqi
>>>
>>>
>>>
>>> --
>>> Born in Roswell... married an alien...
>>> http://emptyhammock.com/
>>> http://edjective.org/
>>>
>>>
>>>
>>>
>>> --
>>> Born in Roswell... married an alien...
>>> http://emptyhammock.com/
>>> http://edjective.org/
>>>
>>> <httpd_trunk_so_reuseport.patch><httpd_trunk_bucket.patch>
>>
>
> <httpd_trunk_so_reuseport.patch><httpd_trunk_bucket.patch>


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