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...@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:j...@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...@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...@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:traw...@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...@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> >
