http://blog.gmane.org/gmane.comp.web.cache.memcached hourly 1 1901-01-01T00:00+00:00 http://gmane.org/img/gmane-25t.png http://gmane.org http://comments.gmane.org/gmane.comp.web.cache.memcached/14252 <pre>Hello, My name is Yuval Meir and I am a M.Sc student in Tel Aviv University. As part of my academic research I have implemented the ARC (Adaptive Replacement Cache) caching policy in Memcached I ran benchmarks using a modified version of memaslap and the results were very good: cache misses were reduced by up to to 30% on some loads, and in terms of run time, memory usage and CPU usage, my implementation performed similar to the original Memcached. I attached the diff (based on Memcached 1.4.13) and the results I have so far in the excel file (note that it has several tabs). ARC was introduced in the following publication by Nimrod Megiddo, Dharmendra Modha: http://www.almaden.ibm.com/cs/people/dmodha/arcfast.pdf which was published in USENIX 2003. I will be very glad to get you reviewes and comments. Regards, Yuval Meir Computer Science department Tel-Aviv University </pre> Yuval M 2012-05-24T19:12:33 http://comments.gmane.org/gmane.comp.web.cache.memcached/14250 <pre>I revised memcached1.4.13 to make cas ID unique between server reboots. But It seemed that two memcached instances on a server has eaten up almost all memory under stressing load. 1. OS: centerOS5.3, 64bit 2. memcached startup command: /opt/memcached1.4.13.0503b/bin/memcached -u nobody -d -m 4096 -c 1024 - l 192.168.8.224 -p 11211 -v &gt; /var/log/memcached-11211.log 2&gt;&amp;1 /opt/memcached1.4.13.0503b/bin/memcached -u nobody -d -m 4096 -c 1024 - l 192.168.8.224 -p 11211 -v &gt; /var/log/memcached-11211.log 2&gt;&amp;1 3. Memory usage: [root&lt; at &gt;dell1-12 ~]# free -m total used free shared buffers cached Mem: 16044 15986 58 0 85 24 -/+ buffers/cache: 15876 168 Swap: 7820 6911 908 Stats on one instance: stats STAT pid 32205 STAT uptime 60090 STAT time 1336177937 STAT version 1.4.13.0503b STAT libevent 1.4.12-stable STAT pointer_size 64 STAT rusage_user 1125.852844 STAT rusage_system 2174.782382 STAT curr_connection</pre> Smiling Ai 2012-05-05T02:36:18 http://comments.gmane.org/gmane.comp.web.cache.memcached/14249 <pre>Hi! Added support for setting options via ENV variable LIBMEMCACHED. Fix corner case on last used result. Bug fixes. http://launchpad.net/libmemcached Cheers, -Brian</pre> Brian Aker 2012-05-23T07:42:50 http://comments.gmane.org/gmane.comp.web.cache.memcached/14243 <pre>Status: New Owner: ---- Labels: Type-Defect Priority-Medium New issue 274 by vlak...&lt; at &gt;gmail.com: typo in memcached wiki http://code.google.com/p/memcached/issues/detail?id=274 http://code.google.com/p/memcached/wiki/NewInstallFromPackage s/rececnt/recent </pre> memcached< at >googlecode.com 2012-05-20T17:31:39 http://comments.gmane.org/gmane.comp.web.cache.memcached/14241 <pre>We are currently having an issue with our memcache server that appears to be flushing data even though nothing in the apps are flushing data. I can set something with a TTL of 2 weeks yet it is only lasting in memcache for a max of something around 30 minutes. Print out of getstats in one of the php applications shows the following: Array ( [pid] =&gt; 24793 [uptime] =&gt; 373575 [time] =&gt; 1336770386 [version] =&gt; 1.4.2 [pointer_size] =&gt; 64 [rusage_user] =&gt; 4077.050000 [rusage_system] =&gt; 12475.330000 [curr_connections] =&gt; 1143 [total_connections] =&gt; 89011605 [connection_structures] =&gt; 1616 [cmd_get] =&gt; 438522590 [cmd_set] =&gt; 101189934 [cmd_flush] =&gt; 863 [get_hits] =&gt; 435589695 [get_misses] =&gt; 188087908 [delete_misses] =&gt; 27221748 [delete_hits] =&gt; 610097 [incr_misses] =&gt; 0 [incr_hits] =&gt; 0 [decr_misses] =&gt; 0 [decr_hits] =&gt; 0 [cas_misses] =&gt; 0 [cas_hits] =&gt; 0 [cas_badval] =&gt; 0 [bytes_read] =&gt; 71199529191 [bytes_w</pre> Mentch 2012-05-11T21:31:16 http://comments.gmane.org/gmane.comp.web.cache.memcached/14230 <pre>When we are under high load (10k+ requests per second) we start getting communication failures (connection timouts,closed connection during header) to memcached. After a small period of time in this state we start getting mangled returns from the cache. Some returns will contain two pages data, some will simply be the wrong entry. We can recover from this by resetting the memcache servers. Is there some connection concurrency limit we may be bumping into under high load that would cause communication channel mismatches, such that request 1 will somehow receive request 2's answer? We are using memcached 1.4.11 with the following config on x86_64 -d -p 11211 -u memcached -m 1024 -c 1024 </pre> Greg Grensteiner 2012-05-10T20:27:35 http://comments.gmane.org/gmane.comp.web.cache.memcached/14229 <pre>hi , I write a client of memcached myselves,I string the command like "get key1\r\nget key2\r\nget key3\r\nget key4\r\n.......get key500\r \n",when I send it to the memcached server by socket,I get only 460~480 values or less.I doubt it's the bug of the libevent! who can tell me. </pre> casa zhang 2012-05-10T11:06:35 http://comments.gmane.org/gmane.comp.web.cache.memcached/14224 <pre>Status: New Owner: ---- Labels: Type-Defect Priority-Medium New issue 273 by DanseL...&lt; at &gt;gmail.com: Compilation issue on v2.0.19 http://code.google.com/p/memcached/issues/detail?id=273 Hello everyone, Here is my little problem about compilation What steps will reproduce the problem? 1. ./configure 2. make &amp;&amp; make test What is the expected output? What do you see instead? The result is as follows: $ make &amp;&amp; make test make all-recursive make[1]: ディレクトリ `/cygdrive/c/Documents and Settings/ksksol/My Documents/libevent-2.0.19-stable' に入ります Making all in . make[2]: ディレクトリ `/cygdrive/c/Documents and Settings/ksksol/My Documents/libevent-2.0.19-stable' に入ります make[2]: ディレクトリ `/cygdrive/c/Documents and Settings/ksksol/My Documents/libevent-2.0.19-stable' から出ます Making all in include make[2]: ディレクトリ `/cygdrive/c/Documents and Settings/ksksol/My Documents/libevent-2.0.19-stable/include' に入ります make[2]: `all' に対して</pre> memcached< at >googlecode.com 2012-05-09T07:09:56 http://comments.gmane.org/gmane.comp.web.cache.memcached/14216 <pre>Status: New Owner: ---- Labels: Type-Defect Priority-Medium New issue 272 by keyurgov...&lt; at &gt;gmail.com: Memcached "hung" in do_item_alloc http://code.google.com/p/memcached/issues/detail?id=272 What is the problem? One night at Etsy, we started getting a flood of memcached errors. We were seeing out-of-memory errors when trying to set/add any value into slab #4. The slab held data of sizes upto 10 bytes. I did some low-level checking around what happens in do_item_alloc() because we hadn't built debug-symbols :( Details here: https://gist.github.com/2634998 Starting with search = tails[id]; in line 106. The code's here: https://github.com/memcached/memcached/blob/master/items.c The search item has a starting ref count of 2. So calling refcount_incr on it makes it 3 and it entirely skips the block of code between 107 and 152 (that block handles expired items and forcible eviction). In the else block in line 154, since the slab is full, slabs_alloc returns NULL. In line 156, the refcount is </pre> memcached< at >googlecode.com 2012-05-08T13:37:56 http://comments.gmane.org/gmane.comp.web.cache.memcached/14214 <pre>Hi all, I want make a slight extension to memcached server, and I have several new source files to be added to the build system. What files shall I modify? How to change? Thanks! -sharc </pre> sharc 2012-05-08T04:48:21 http://comments.gmane.org/gmane.comp.web.cache.memcached/14212 <pre>Status: New Owner: ---- Labels: Type-Defect Priority-Medium New issue 271 by zhega...&lt; at &gt;gmail.com: Spontaneous quits on Solaris http://code.google.com/p/memcached/issues/detail?id=271 What steps will reproduce the problem? 1. Get a memcached 2. Build it on Solaris 10 3. Run it. What is the expected output? What do you see instead? Expected output is none. I see instead something like this: rcurr=30eb2b0 ritem=12740d1f rbuf=30e9c10 rlbytes=1070 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=10acb12c ritem=11eea05b rbuf=10aca010 rlbytes=2467 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=10cc6eb0 ritem=11f77c3f rbuf=10cc5810 rlbytes=1403 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=10e08d08 ritem=11ed6ef7 rbuf=10e07c10 rlbytes=2513 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=20b5db7 ritem=11f77746 rbuf=20b4c10 rlbytes=2656 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 r</pre> memcached< at >googlecode.com 2012-05-04T03:41:39 http://comments.gmane.org/gmane.comp.web.cache.memcached/14208 <pre>Hi, I want to know if there is a way to alter the default cache eviction policy used by memcached(LRU). I want to implement an LFU cache(or an SDC Cache replacement policy) and wondering if I can use memcached or not? Regards, Arghyadip </pre> Arghyadip Paul 2012-05-03T07:23:26 http://comments.gmane.org/gmane.comp.web.cache.memcached/14206 <pre>Hi. I have 1.4.13 on Solaris x86_64. Sometimes it just quits. To inversigate this, I launched it with -v in a screen. It works for now, but it constantly shows some errors: ===Cut=== rcurr=283e52c ritem=1afc85b rbuf=283d410 rlbytes=2422 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=29b9508 ritem=1ab5676 rbuf=29b8410 rlbytes=2152 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=20b1508 ritem=1adf076 rbuf=20b0410 rlbytes=2246 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=2896eb0 ritem=1afcddf rbuf=2895810 rlbytes=797 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=261a508 ritem=1aece77 rbuf=2619410 rlbytes=2669 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=29cb548 ritem=1596f28 rbuf=29ca410 rlbytes=345 rsize=8192 Failed to read, and not due to blocking: errno: 0 Error 0 rcurr=29b4d08 ritem=1afe3f6 rbuf=29b3c10 rlbytes=2246 rsize=8192 Failed to read, and not due to block</pre> Eugene M. Zheganin 2012-05-03T04:52:03 http://comments.gmane.org/gmane.comp.web.cache.memcached/14205 <pre>Hi All i have to manage 3 servers with a rails application, i would like to put only one memcached daemon on one of these servers. this cache must be shared from the servers. 2 servers must connect remotly, 1 locally do you see any problem on this solution if i set the same domain in each rails app? Any suggestion? Thanks Mauro Giannandrea </pre> Mauro Giannandrea 2012-05-02T21:16:16 http://comments.gmane.org/gmane.comp.web.cache.memcached/14201 <pre>Hi! Changelog: * Add API call for exist calls. * Update all license files to be BSD. http://launchpad.net/libmemcached Cheers, -Brian</pre> Brian Aker 2012-04-29T03:16:27 http://comments.gmane.org/gmane.comp.web.cache.memcached/14196 <pre>*There are only two hard things in Computer Science: cache invalidation and naming things. </pre> Jakub Łopuszański 2012-04-27T22:14:49 http://comments.gmane.org/gmane.comp.web.cache.memcached/14194 <pre>Hi, will using append() on an item put it to the top of the LRU as an add() does? Cheers Martin </pre> Martin Hellmich 2012-04-27T08:10:49 http://comments.gmane.org/gmane.comp.web.cache.memcached/14178 <pre>Hi all, I compiled and installed Memcached 1.4.3 from source: http://memcached.googlecode.com/files/memcached-1.4.13.tar.gz The configuration is quite simple: ./configure --prefix=/usr/local/ memcached It works if I install it on a dedicated Ubuntu 11 server. However, it does not work on Linode's Ubuntu 11 VM (Xen-based) The source code can be compilable, installable. The server can run but it is not responsive. === Telnet access ====== root&lt; at &gt;spica:/home/dev7# telnet 127.0.0.1 11211 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get fdsgfdsf f sdfds f dsadfs ] ^] telnet&gt; quit Connection closed. ============================ The strace output shows that it is running ===== root&lt; at &gt;spica:/sample-app/# ps -eaf | grep mem 1003 17289 1 0 14:49 ? 00:00:00 /usr/local/memcached/ bin/memcached -d -l 127.0.0.1 -p 11211 -u myserver root 17317 29816 0 14:51 pts/1 00:00:00 grep --color=auto mem root&lt; at &gt;spica:/sample-app# strace -p 17289 Process 17289 attached - interrupt to </pre> pcdinh 2012-04-25T15:32:55 http://comments.gmane.org/gmane.comp.web.cache.memcached/14177 <pre>the memcached main process can't accept connect when use assoc_maintenance_thread function,here is the gdb bt result: we have 4 thread : |-memcached,28059 -d -p 12111 -c 8192 -m 16384 -u root -l 127.0.0.1 | |-{memcached},28060 | |-{memcached},28061 | |-{memcached},28062 | |-{memcached},28063 | `-{memcached},28064 gdb bt result: gdb -p 28060 GNU gdb Fedora (6.8-37.el5) Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later &lt;http://gnu.org/licenses/ gpl.html&gt; This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-redhat-linux-gnu". Attaching to process 28060 warning: process 28060 is a cloned process Reading symbols from /usr/local/sinawap/bin/memcached...done. Reading symbols from /usr/local/sinawap/lib/libevent-1.4.so.2...done. Loaded symbols for /usr/local/sinawap/lib/libevent-1.4.so.2 Readi</pre> lee 2012-04-25T14:05:40 http://comments.gmane.org/gmane.comp.web.cache.memcached/14174 <pre>hi,memcached I'm sorry to trouble you! I have one question to ask you. I has started one memcache on port 11211 , if i want to add a new memcache(11212) , there are need to do same thing . So , how can i do that ? Can i want to restart the first memcached on 11211? </pre> 鱼 邹 2012-04-24T09:42:22 http://comments.gmane.org/gmane.comp.web.cache.memcached/14170 <pre>Status: New Owner: ---- Labels: Type-Defect Priority-Medium New issue 270 by malikb...&lt; at &gt;gmail.com: typo on memslap --help http://code.google.com/p/memcached/issues/detail?id=270 What steps will reproduce the problem? memslap --help What is the expected output? What do you see instead? Generates a load against a memcached custer of servers. custer -&gt; cluster What version of the product are you using? On what operating system? memcached1.2.3 </pre> memcached< at >googlecode.com 2012-04-23T15:46:36 Search the mailing list at Gmane query http://search.gmane.org/?group=$group=gmane.comp.web.cache.memcached