在前邊的tomcat session server msm的那篇部落格我們用memcached做tomcat session伺服器，預設官方memcached是不支援主從同步的，為了解決memcached的高可用，我們是在客戶端實現雙寫和排程，把一份session 多次寫入後端的session伺服器上，這樣使得多臺memcached伺服器之間的資料有了冗餘備份，即便叢集中某一臺memcached當機以後，也不會丟失session；在使用者訪問上，我們在客戶端上實現把排程自動切換到沒有當機的memcached上，這樣又保證了線上業務的正常使用；memcached 它沒有redis那種持久化的特點，它的資料上儲存到記憶體中，一旦伺服器掉電，或者重啟服務都會導致資料丟失；
memcached單機部署
1、使用yum安裝memcached
檢視memcached包簡介資訊
[root@slave01 ~]# yum info memcached
Loaded plugins: fastestmirror
Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Available Packages
Name : memcached
Arch : x86_64
Version : 1.4.15
Release : 10.el7_3.1
Size : 85 k
Repo : base/7/x86_64
Summary : High Performance, Distributed Memory Object Cache
URL : http://www.memcached.org/
License : BSD
Description : memcached is a high-performance, distributed memory object caching
: system, generic in nature, but intended for use in speeding up dynamic
: web applications by alleviating database load.
[root@slave01 ~]#
提示：base倉庫收錄memcached的版本上1.4.15;
安裝memcached
[root@slave01 ~]# yum install -y memcached Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com base | 3.6 kB 00:00:00 docker-ce-stable | 3.5 kB 00:00:00 epel | 4.7 kB 00:00:00 extras | 2.9 kB 00:00:00 mariadb | 2.9 kB 00:00:00 updates | 2.9 kB 00:00:00 (1/4): extras/7/x86_64/primary_db | 206 kB 00:00:00 (2/4): updates/7/x86_64/primary_db | 3.8 MB 00:00:00 (3/4): epel/x86_64/primary_db | 6.9 MB 00:00:01 (4/4): epel/x86_64/updateinfo | 1.0 MB 00:00:05 Resolving Dependencies --> Running transaction check ---> Package memcached.x86_64 0:1.4.15-10.el7_3.1 will be installed --> Processing Dependency: libevent-2.0.so.5()(64bit) for package: memcached-1.4.15-10.el7_3.1.x86_64 --> Running transaction check ---> Package libevent.x86_64 0:2.0.21-4.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================================================================== Package Arch Version Repository Size ================================================================================================================================== Installing: memcached x86_64 1.4.15-10.el7_3.1 base 85 k Installing for dependencies: libevent x86_64 2.0.21-4.el7 base 214 k Transaction Summary ================================================================================================================================== Install 1 Package (+1 Dependent package) Total download size: 299 k Installed size: 901 k Downloading packages: (1/2): libevent-2.0.21-4.el7.x86_64.rpm | 214 kB 00:00:00 (2/2): memcached-1.4.15-10.el7_3.1.x86_64.rpm | 85 kB 00:00:00 ---------------------------------------------------------------------------------------------------------------------------------- Total 782 kB/s | 299 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : libevent-2.0.21-4.el7.x86_64 1/2 Installing : memcached-1.4.15-10.el7_3.1.x86_64 2/2 Verifying : memcached-1.4.15-10.el7_3.1.x86_64 1/2 Verifying : libevent-2.0.21-4.el7.x86_64 2/2 Installed: memcached.x86_64 0:1.4.15-10.el7_3.1 Dependency Installed: libevent.x86_64 0:2.0.21-4.el7 Complete! [root@slave01 ~]#
提示：從上面的安裝資訊可以看到memcached依賴libevent這個包，原因是Memcache 藉助了作業系統的 libevent 工具做高效的讀寫。libevent 是個程式庫，它將 Linux 的 epoll、BSD 類作業系統的 kqueue 等事件處理功能封裝成統一的介面。即使對伺服器的連線數增加，也能發揮高效能。memcached 使用這個 libevent 庫，因此能在 Linux、BSD、Solaris 等作業系統上發揮其高效能；
檢視memcached程式環境
[root@slave01 ~]# rpm -ql memcached /etc/sysconfig/memcached /usr/bin/memcached /usr/bin/memcached-tool /usr/lib/systemd/system/memcached.service /usr/share/doc/memcached-1.4.15 /usr/share/doc/memcached-1.4.15/AUTHORS /usr/share/doc/memcached-1.4.15/CONTRIBUTORS /usr/share/doc/memcached-1.4.15/COPYING /usr/share/doc/memcached-1.4.15/ChangeLog /usr/share/doc/memcached-1.4.15/NEWS /usr/share/doc/memcached-1.4.15/README.md /usr/share/doc/memcached-1.4.15/protocol.txt /usr/share/doc/memcached-1.4.15/readme.txt /usr/share/doc/memcached-1.4.15/threads.txt /usr/share/man/man1/memcached-tool.1.gz /usr/share/man/man1/memcached.1.gz [root@slave01 ~]#
提示：/etc/sysconfig/memcached這個檔案是memcached的配置檔案，/usr/bin/memcached是可執行程式；/usr/lib/systemd/system/memcached.service是memcached的unit file檔案；
檢視配置檔案
[root@slave01 ~]# cat /etc/sysconfig/memcached PORT="11211" USER="memcached" MAXCONN="1024" CACHESIZE="64" OPTIONS="" [root@slave01 ~]#
提示：PORT用於指定memcached的監聽埠，預設是11211，USER用於指定啟動memcached的使用者，預設是memcached，MAXCONN用於指定最大連線數，預設1024.CACHESIZE用於指定最大記憶體，預設是64M，OPTIONS用於指定其他選項的；
檢視memcached幫助
[root@slave01 ~]# memcached -h
memcached 1.4.15
-p <num> TCP port number to listen on (default: 11211)
-U <num> UDP port number to listen on (default: 11211, 0 is off)
-s <file> UNIX socket path to listen on (disables network support)
-a <mask> access mask for UNIX socket, in octal (default: 0700)
-l <addr> interface to listen on (default: INADDR_ANY, all addresses)
<addr> may be specified as host:port. If you don't specify
a port number, the value you specified with -p or -U is
used. You may specify multiple addresses separated by comma
or by using -l multiple times
-d run as a daemon
-r maximize core file limit
-u <username> assume identity of <username> (only when run as root)
-m <num> max memory to use for items in megabytes (default: 64 MB)
-M return error on memory exhausted (rather than removing items)
-c <num> max simultaneous connections (default: 1024)
-k lock down all paged memory. Note that there is a
limit on how much memory you may lock. Trying to
allocate more than that would fail, so be sure you
set the limit correctly for the user you started
the daemon with (not for -u <username> user;
under sh this is done with 'ulimit -S -l NUM_KB').
-v verbose (print errors/warnings while in event loop)
-vv very verbose (also print client commands/reponses)
-vvv extremely verbose (also print internal state transitions)
-h print this help and exit
-i print memcached and libevent license
-P <file> save PID in <file>, only used with -d option
-f <factor> chunk size growth factor (default: 1.25)
-n <bytes> minimum space allocated for key+value+flags (default: 48)
-L Try to use large memory pages (if available). Increasing
the memory page size could reduce the number of TLB misses
and improve the performance. In order to get large pages
from the OS, memcached will allocate the total item-cache
in one large chunk.
-D <char> Use <char> as the delimiter between key prefixes and IDs.
This is used for per-prefix stats reporting. The default is
":" (colon). If this option is specified, stats collection
is turned on automatically; if not, then it may be turned on
by sending the "stats detail on" command to the server.
-t <num> number of threads to use (default: 4)
-R Maximum number of requests per event, limits the number of
requests process for a given connection to prevent
starvation (default: 20)
-C Disable use of CAS
-b <num> Set the backlog queue limit (default: 1024)
-B Binding protocol - one of ascii, binary, or auto (default)
-I Override the size of each slab page. Adjusts max item size
(default: 1mb, min: 1k, max: 128m)
-S Turn on Sasl authentication
-o Comma separated list of extended or experimental options
- (EXPERIMENTAL) maxconns_fast: immediately close new
connections if over maxconns limit
- hashpower: An integer multiplier for how large the hash
table should be. Can be grown at runtime if not big enough.
Set this based on "STAT hash_power_level" before a
restart.
[root@slave01 ~]#
提示：-P用於指定監聽TCP埠，預設11211；-U用於指定監聽UDP埠，預設也是11211，如果指定是0表示關閉UDP監聽；-s用於指定unix socket檔案；-a用於指定unix socket檔案的許可權，預設是0700的許可權；-l用於指定監聽的ip地址資訊，預設是監聽本機所有可用地址；-d 用於指定memcached執行為守護程式；-r用於限定core file的大小；-u用於指定執行memcached的使用者名稱稱；-m用於指定分配給memcached使用的記憶體，單位是MB；-M用於指定記憶體耗盡時返回錯誤，而不是刪除；-c指定最大連線數，預設數1024；-k用於指定鎖定所有分頁記憶體。-v -vv -vvv 列印詳細資訊，v的數量越多，表示列印的資訊就越詳細；-h列印幫助資訊；-i列印memcached和libevent的license資訊；-p用於指定pid檔案；-f用於指定chunk 增長因子，預設數1.25；-n用於指定為快取資料項的key、value、flag設定最小分配位元組數，預設是48；-L用於指定嘗試使用大記憶體分頁；-D用於指定統計報告中Key字首和ID之間的分隔符，預設是冒號“:”；-t用於指定處理執行緒的數量，預設數4；-R用於指定對連續達到的客戶端請求數設定一個限額，如果超過該設定，會選擇另一個連線來處理請求，預設為20；-C用於指定關閉CAS;-b使用者指定backlog佇列長度，預設是1024；-B用於指定使用的協議，預設行為是自動協商（autonegotiate），可能使用的選項有auto、ascii、binary。-I用於指定覆蓋預設的STAB頁大小，預設是1M；-S用於指定開啟Sasl身份驗證；-o用於指定號分隔的選項，一般用於用於擴充套件或實驗性質的選項；
啟動memecached
提示：啟動memcached可以把啟動的選項寫到配置檔案，然後使用systemctl方式啟動，也可以直接在命令列使用memcached命令指定選項啟動；
到此，單機memcached就安裝啟動完成；
2、memcached編譯安裝
安裝編譯環境
root@slave01 ~]# yum groupinstall "development tools" -y Loaded plugins: fastestmirror There is no installed groups file. Maybe run: yum groups mark convert (see man yum) Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com Resolving Dependencies --> Running transaction check ---> Package autoconf.noarch 0:2.69-11.el7 will be installed --> Processing Dependency: m4 >= 1.4.14 for package: autoconf-2.69-11.el7.noarch ---> Package automake.noarch 0:1.13.4-3.el7 will be installed --> Processing Dependency: perl(Thread::Queue) for package: automake-1.13.4-3.el7.noarch --> Processing Dependency: perl(TAP::Parser) for package: automake-1.13.4-3.el7.noarch ---> Package bison.x86_64 0:3.0.4-2.el7 will be installed ---> Package byacc.x86_64 0:1.9.20130304-3.el7 will be installed ……省略部分內容…… Installed: autoconf.noarch 0:2.69-11.el7 automake.noarch 0:1.13.4-3.el7 bison.x86_64 0:3.0.4-2.el7 byacc.x86_64 0:1.9.20130304-3.el7 cscope.x86_64 0:15.8-10.el7 ctags.x86_64 0:5.8-13.el7 diffstat.x86_64 0:1.57-4.el7 doxygen.x86_64 1:1.8.5-4.el7 elfutils.x86_64 0:0.176-4.el7 flex.x86_64 0:2.5.37-6.el7 gcc.x86_64 0:4.8.5-39.el7 gcc-c++.x86_64 0:4.8.5-39.el7 gcc-gfortran.x86_64 0:4.8.5-39.el7 git.x86_64 0:1.8.3.1-23.el7_8 indent.x86_64 0:2.2.11-13.el7 intltool.noarch 0:0.50.2-7.el7 libtool.x86_64 0:2.4.2-22.el7_3 patch.x86_64 0:2.7.1-12.el7_7 patchutils.x86_64 0:0.3.3-4.el7 rcs.x86_64 0:5.9.0-7.el7 redhat-rpm-config.noarch 0:9.1.0-88.el7.centos rpm-build.x86_64 0:4.11.3-43.el7 rpm-sign.x86_64 0:4.11.3-43.el7 subversion.x86_64 0:1.7.14-14.el7 swig.x86_64 0:2.0.10-5.el7 systemtap.x86_64 0:4.0-11.el7 Dependency Installed: apr.x86_64 0:1.4.8-5.el7 apr-util.x86_64 0:1.5.2-6.el7 boost-date-time.x86_64 0:1.53.0-28.el7 boost-system.x86_64 0:1.53.0-28.el7 boost-thread.x86_64 0:1.53.0-28.el7 bzip2.x86_64 0:1.0.6-13.el7 cpp.x86_64 0:4.8.5-39.el7 dwz.x86_64 0:0.11-3.el7 dyninst.x86_64 0:9.3.1-3.el7 efivar-libs.x86_64 0:36-12.el7 emacs-filesystem.noarch 1:24.3-23.el7 gdb.x86_64 0:7.6.1-119.el7 gettext-common-devel.noarch 0:0.19.8.1-3.el7 gettext-devel.x86_64 0:0.19.8.1-3.el7 glibc-devel.x86_64 0:2.17-307.el7.1 glibc-headers.x86_64 0:2.17-307.el7.1 gnutls.x86_64 0:3.3.29-9.el7_6 kernel-debug-devel.x86_64 0:3.10.0-1127.18.2.el7 kernel-headers.x86_64 0:3.10.0-1127.18.2.el7 libdwarf.x86_64 0:20130207-4.el7 libgfortran.x86_64 0:4.8.5-39.el7 libmodman.x86_64 0:2.0.1-8.el7 libmpc.x86_64 0:1.0.1-3.el7 libproxy.x86_64 0:0.4.11-11.el7 libquadmath.x86_64 0:4.8.5-39.el7 libquadmath-devel.x86_64 0:4.8.5-39.el7 libstdc++-devel.x86_64 0:4.8.5-39.el7 m4.x86_64 0:1.4.16-10.el7 mokutil.x86_64 0:15-8.el7 mpfr.x86_64 0:3.1.1-4.el7 neon.x86_64 0:0.30.0-4.el7 nettle.x86_64 0:2.7.1-8.el7 pakchois.x86_64 0:0.4-10.el7 perl-Error.noarch 1:0.17020-2.el7 perl-Git.noarch 0:1.8.3.1-23.el7_8 perl-TermReadKey.x86_64 0:2.30-20.el7 perl-Test-Harness.noarch 0:3.28-3.el7 perl-Thread-Queue.noarch 0:3.02-2.el7 perl-XML-Parser.x86_64 0:2.41-10.el7 perl-srpm-macros.noarch 0:1-8.el7 python-srpm-macros.noarch 0:3-32.el7 subversion-libs.x86_64 0:1.7.14-14.el7 systemtap-client.x86_64 0:4.0-11.el7 systemtap-devel.x86_64 0:4.0-11.el7 systemtap-runtime.x86_64 0:4.0-11.el7 trousers.x86_64 0:0.3.14-2.el7 unzip.x86_64 0:6.0-21.el7 zip.x86_64 0:3.0-11.el7 Complete! [root@slave01 ~]#
安裝依賴包
[root@slave01 ~]# yum install -y libevent-devel Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com Resolving Dependencies --> Running transaction check ---> Package libevent-devel.x86_64 0:2.0.21-4.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ===================================================================================================== Package Arch Version Repository Size ===================================================================================================== Installing: libevent-devel x86_64 2.0.21-4.el7 base 85 k Transaction Summary ===================================================================================================== Install 1 Package Total download size: 85 k Installed size: 357 k Downloading packages: libevent-devel-2.0.21-4.el7.x86_64.rpm | 85 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : libevent-devel-2.0.21-4.el7.x86_64 1/1 Verifying : libevent-devel-2.0.21-4.el7.x86_64 1/1 Installed: libevent-devel.x86_64 0:2.0.21-4.el7 Complete! [root@slave01 ~]#
下載原始碼檔案
[root@slave01 ~]# wget http://memcached.org/files/memcached-1.6.6.tar.gz --2020-08-11 10:35:25-- http://memcached.org/files/memcached-1.6.6.tar.gz Resolving memcached.org (memcached.org)... 107.170.231.145 Connecting to memcached.org (memcached.org)|107.170.231.145|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 543661 (531K) [application/octet-stream] Saving to: ‘memcached-1.6.6.tar.gz’ 100%[===========================================================>] 543,661 19.9KB/s in 17s 2020-08-11 10:35:43 (30.5 KB/s) - ‘memcached-1.6.6.tar.gz’ saved [543661/543661] [root@slave01 ~]# ls memcached-1.6.6.tar.gz [root@slave01 ~]#
解壓原始碼包，檢查編譯環境
[root@slave01 ~]# tar xf memcached-1.6.6.tar.gz [root@slave01 ~]# cd memcached-1.6.6/ [root@slave01 memcached-1.6.6]# ls aclocal.m4 COPYING itoa_ljust.h NEWS stats_prefix.c assoc.c crawler.c jenkins_hash.c openbsd_priv.c stats_prefix.h assoc.h crawler.h jenkins_hash.h protocol_binary.h storage.c authfile.c crc32c.c LICENSE.bipbuffer README.md storage.h authfile.h crc32c.h linux_priv.c restart.c t AUTHORS daemon.c logger.c restart.h testapp.c bipbuffer.c depcomp logger.h sasl_defs.c thread.c bipbuffer.h doc m4 sasl_defs.h timedrun.c cache.c extstore.c Makefile.am scripts tls.c cache.h extstore.h Makefile.in sizes.c tls.h ChangeLog freebsd_priv.c memcached.c slab_automove.c trace.h compile hash.c memcached_dtrace.d slab_automove_extstore.c util.c config.guess hash.h memcached.h slab_automove_extstore.h util.h config.h.in install-sh memcached.spec slab_automove.h version.m4 config.sub items.c missing slabs.c configure items.h murmur3_hash.c slabs.h configure.ac itoa_ljust.c murmur3_hash.h solaris_priv.c [root@slave01 memcached-1.6.6]# ./configure --prefix=/usr/locat/memcached checking build system type... x86_64-pc-linux-gnu checking host system type... x86_64-pc-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... /usr/bin/mkdir -p checking for gawk... gawk checking whether make sets $(MAKE)... yes checking whether make supports nested variables... yes ……省略部分內容…… checking for xsltproc... /usr/bin/xsltproc checking that generated files are newer than configure... done configure: creating ./config.status config.status: creating Makefile config.status: creating doc/Makefile config.status: creating config.h config.status: executing depfiles commands [root@slave01 memcached-1.6.6]#
編譯安裝memcached
[root@slave01 memcached-1.6.6]# make make all-recursive make[1]: Entering directory `/root/memcached-1.6.6' Making all in doc make[2]: Entering directory `/root/memcached-1.6.6/doc' make all-am make[3]: Entering directory `/root/memcached-1.6.6/doc' make[3]: Nothing to be done for `all-am'. make[3]: Leaving directory `/root/memcached-1.6.6/doc' make[2]: Leaving directory `/root/memcached-1.6.6/doc' make[2]: Entering directory `/root/memcached-1.6.6' gcc -std=gnu99 -DHAVE_CONFIG_H -I. -DNDEBUG -g -O2 -pthread -pthread -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -MT memcached-memcached.o -MD -MP -MF .deps/memcached-memcached.Tpo -c -o memcached-memcached.o `test -f 'memcached.c' || echo './'`memcached.c mv -f .deps/memcached-memcached.Tpo .deps/memcached-memcached.Po gcc -std=gnu99 -DHAVE_CONFIG_H -I. -DNDEBUG -g -O2 -pthread -pthread -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -MT memcached-hash.o -MD -MP -MF .deps/memcached-hash.Tpo -c -o memcached-hash.o `test -f 'hash.c' || echo './'`hash.c mv -f .deps/memcached-hash.Tpo .deps/memcached-hash.Po ……省略部分內容…… gcc -std=gnu99 -DHAVE_CONFIG_H -I. -g -O2 -pthread -pthread -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -MT timedrun.o -MD -MP -MF .deps/timedrun.Tpo -c -o timedrun.o timedrun.c mv -f .deps/timedrun.Tpo .deps/timedrun.Po gcc -std=gnu99 -g -O2 -pthread -pthread -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -o timedrun timedrun.o -levent make[2]: Leaving directory `/root/memcached-1.6.6' make[1]: Leaving directory `/root/memcached-1.6.6' [root@slave01 memcached-1.6.6]# make install make install-recursive make[1]: Entering directory `/root/memcached-1.6.6' Making install in doc make[2]: Entering directory `/root/memcached-1.6.6/doc' make install-am make[3]: Entering directory `/root/memcached-1.6.6/doc' make[4]: Entering directory `/root/memcached-1.6.6/doc' make[4]: Nothing to be done for `install-exec-am'. /usr/bin/mkdir -p '/usr/locat/memcached/share/man/man1' /usr/bin/install -c -m 644 memcached.1 '/usr/locat/memcached/share/man/man1' make[4]: Leaving directory `/root/memcached-1.6.6/doc' make[3]: Leaving directory `/root/memcached-1.6.6/doc' make[2]: Leaving directory `/root/memcached-1.6.6/doc' make[2]: Entering directory `/root/memcached-1.6.6' make[3]: Entering directory `/root/memcached-1.6.6' /usr/bin/mkdir -p '/usr/locat/memcached/bin' /usr/bin/install -c memcached '/usr/locat/memcached/bin' /usr/bin/mkdir -p '/usr/locat/memcached/include/memcached' /usr/bin/install -c -m 644 protocol_binary.h '/usr/locat/memcached/include/memcached' make[3]: Leaving directory `/root/memcached-1.6.6' make[2]: Leaving directory `/root/memcached-1.6.6' make[1]: Leaving directory `/root/memcached-1.6.6' [root@slave01 memcached-1.6.6]# ll /usr/locat/memcached/ total 0 drwxr-xr-x 2 root root 23 Aug 11 10:39 bin drwxr-xr-x 3 root root 23 Aug 11 10:39 include drwxr-xr-x 3 root root 17 Aug 11 10:39 share [root@slave01 memcached-1.6.6]#
啟動memcached
到此memcached的編譯安裝就完成了
3、使用python連線memcached寫入資料
[root@slave01 ~]# cat test.py
import memcache
m = memcache.Client(['127.0.0.1:11211'], debug=True)
for i in range(100):
m.set("key%d" % i,"v%d" % i)
# ret = m.get('key%d' % i)
# print ret
[root@slave01 ~]#
提示：以上指令碼主要作用是連線到memcache後迴圈寫入100個key；
執行指令碼，然後檢視memcached上是否儲存的有我們寫入的key資料？
[root@slave01 ~]# python test.py [root@slave01 ~]# telnet 127.0.0.1 11211 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. get key1 VALUE key1 0 2 v1 END get k12 END get key12 VALUE key12 0 3 v12 END quit Connection closed by foreign host. [root@slave01 ~]#
提示：可以看到執行指令碼以後，連線到memcached裡是可以取出我們寫入到key對應的資料；
部署 repcached
實驗環境說明
| 名稱 | IP地址 | 埠 |
| master01 | 192.168.16.196 | 11211 |
| master02 | 192.168.16.197 |
11211 |
在master01上編譯安裝repcached
[root@master01 ~]# ls memcached-1.2.8-repcached-2.2.tar.gz [root@master01 ~]# tar xf memcached-1.2.8-repcached-2.2.tar.gz [root@master01 ~]# ls memcached-1.2.8-repcached-2.2 memcached-1.2.8-repcached-2.2.tar.gz [root@master01 ~]# cd memcached-1.2.8-repcached-2.2/ [root@master01 memcached-1.2.8-repcached-2.2]# ./configure --prefix=/usr/local/repcached --enable-replication checking build system type... Invalid configuration `x86_64-unknown-linux-': machine `x86_64-unknown-linux' not recognized configure: error: /bin/sh ./config.sub x86_64-unknown-linux- failed [root@master01 memcached-1.2.8-repcached-2.2]#
提示：遇到以上錯誤，上因為沒有安裝gcc編譯導致的，通常在Linux上做編譯操作，我們需要先安裝好編譯環境；
安裝編譯環境
[root@master01 memcached-1.2.8-repcached-2.2]# yum groupinstall "development tools" -y
再次編譯
[root@master01 memcached-1.2.8-repcached-2.2]# ./configure --prefix=/usr/local/repcached --enable-replication
checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
checking target system type... x86_64-unknown-linux-gnu
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for style of include used by make... GNU
checking dependency style of gcc... gcc3
checking whether gcc and cc understand -c and -o together... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking for libevent directory... configure: error: libevent is required. You can get it from http://www.monkey.org/~provos/libevent/
If it's already installed, specify its path using --with-libevent=/dir/
[root@master01 memcached-1.2.8-repcached-2.2]#
提示：上述錯誤是沒有檢查到libevent，解決辦法安裝依賴包libevent-devel包
安裝依賴包
[root@master01 memcached-1.2.8-repcached-2.2]# yum install libevent-devel -y
再次檢查
[root@master01 memcached-1.2.8-repcached-2.2]# ./configure --prefix=/usr/local/repcached --enable-replication checking build system type... x86_64-unknown-linux-gnu checking host system type... x86_64-unknown-linux-gnu checking target system type... x86_64-unknown-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... /usr/bin/mkdir -p checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for gcc... gcc checking for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking for style of include used by make... GNU checking dependency style of gcc... gcc3 checking whether gcc and cc understand -c and -o together... yes checking for a BSD-compatible install... /usr/bin/install -c checking for libevent directory... (system) checking for library containing socket... none required checking for library containing gethostbyname... none required checking for library containing mallinfo... none required checking for daemon... yes checking how to run the C preprocessor... gcc -E checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking for stdbool.h that conforms to C99... yes checking for _Bool... yes checking for an ANSI C-conforming const... yes checking malloc.h usability... yes checking malloc.h presence... yes checking for malloc.h... yes checking for struct mallinfo.arena... yes checking for socklen_t... yes checking for endianness... little checking for mlockall... yes checking for getpagesizes... no checking for memcntl... no configure: creating ./config.status config.status: creating Makefile config.status: creating doc/Makefile config.status: creating config.h config.status: executing depfiles commands [root@master01 memcached-1.2.8-repcached-2.2]#
提示：檢查編譯環境沒有問題後，就可以執行編譯和安裝了；
編譯安裝
[root@master01 memcached-1.2.8-repcached-2.2]# make && make install
make all-recursive
make[1]: Entering directory `/root/memcached-1.2.8-repcached-2.2'
Making all in doc
make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2/doc'
make[2]: Nothing to be done for `all'.
make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2/doc'
make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2'
gcc -DHAVE_CONFIG_H -I. -DNDEBUG -g -O2 -MT memcached-memcached.o -MD -MP -MF .deps/memcached-memcached.Tpo -c -o memcached-memcached.o `test -f 'memcached.c' || echo './'`memcached.c
memcached.c: In function ‘add_iov’:
memcached.c:696:30: error: ‘IOV_MAX’ undeclared (first use in this function)
if (m->msg_iovlen == IOV_MAX ||
^
memcached.c:696:30: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [memcached-memcached.o] Error 1
make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/root/memcached-1.2.8-repcached-2.2'
make: *** [all] Error 2
[root@master01 memcached-1.2.8-repcached-2.2]#
提示：這個錯誤是memcached.c中的巨集定義問題，處理辦法就是把memcached.c中的#if defined(__FreeBSD__) || defined(__APPLE__) 和#endif註釋掉即可如下
提示：修改了上面的memcached.c 以後，再次編譯就沒有問題了
再次編譯
[root@master01 memcached-1.2.8-repcached-2.2]# make && make install make all-recursive make[1]: Entering directory `/root/memcached-1.2.8-repcached-2.2' Making all in doc make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2/doc' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2/doc' make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2' gcc -DHAVE_CONFIG_H -I. -DNDEBUG -g -O2 -MT memcached-memcached.o -MD -MP -MF .deps/memcached-memcached.Tpo -c -o memcached-memcached.o `test -f 'memcached.c' || echo './'`memcached.c mv -f .deps/memcached-memcached.Tpo .deps/memcached-memcached.Po gcc -DHAVE_CONFIG_H -I. -DNDEBUG -g -O2 -MT memcached-slabs.o -MD -MP -MF .deps/memcached-slabs.Tpo -c -o memcached-slabs.o `test -f 'slabs.c' || echo './'`slabs.c mv -f .deps/memcached-slabs.Tpo .deps/memcached-slabs.Po ……省略部分內容…… mv -f .deps/replication.Tpo .deps/replication.Po gcc -g -O2 -o memcached-debug memcached.o slabs.o items.o assoc.o thread.o stats.o replication.o -levent make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2' make[1]: Leaving directory `/root/memcached-1.2.8-repcached-2.2' Making install in doc make[1]: Entering directory `/root/memcached-1.2.8-repcached-2.2/doc' make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2/doc' make[2]: Nothing to be done for `install-exec-am'. test -z "/usr/local/repcached/share/man/man1" || /usr/bin/mkdir -p "/usr/local/repcached/share/man/man1" /usr/bin/install -c -m 644 './memcached.1' '/usr/local/repcached/share/man/man1/memcached.1' make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2/doc' make[1]: Leaving directory `/root/memcached-1.2.8-repcached-2.2/doc' make[1]: Entering directory `/root/memcached-1.2.8-repcached-2.2' make[2]: Entering directory `/root/memcached-1.2.8-repcached-2.2' test -z "/usr/local/repcached/bin" || /usr/bin/mkdir -p "/usr/local/repcached/bin" /usr/bin/install -c 'memcached' '/usr/local/repcached/bin/memcached' /usr/bin/install -c 'memcached-debug' '/usr/local/repcached/bin/memcached-debug' make[2]: Nothing to be done for `install-data-am'. make[2]: Leaving directory `/root/memcached-1.2.8-repcached-2.2' make[1]: Leaving directory `/root/memcached-1.2.8-repcached-2.2' [root@master01 memcached-1.2.8-repcached-2.2]# ll /usr/local/repcached/ total 0 drwxr-xr-x 2 root root 46 Aug 10 23:26 bin drwxr-xr-x 3 root root 17 Aug 10 23:26 share [root@master01 memcached-1.2.8-repcached-2.2]# ll /usr/local/repcached/bin/ total 472 -rwxr-xr-x 1 root root 233096 Aug 10 23:26 memcached -rwxr-xr-x 1 root root 248008 Aug 10 23:26 memcached-debug [root@master01 memcached-1.2.8-repcached-2.2]#
提示：可以看到對應目錄下已經有二進位制檔案產生，到此repcached就編譯安裝好了；
驗證repcached/bin/memcached是否可執行？
[root@master01 ~]# /usr/local/repcached/bin/memcached -h
memcached 1.2.8
repcached 2.2
-p <num> TCP port number to listen on (default: 11211)
-U <num> UDP port number to listen on (default: 11211, 0 is off)
-s <file> unix socket path to listen on (disables network support)
-a <mask> access mask for unix socket, in octal (default 0700)
-l <ip_addr> interface to listen on, default is INDRR_ANY
-d run as a daemon
-r maximize core file limit
-u <username> assume identity of <username> (only when run as root)
-m <num> max memory to use for items in megabytes, default is 64 MB
-M return error on memory exhausted (rather than removing items)
-c <num> max simultaneous connections, default is 1024
-k lock down all paged memory. Note that there is a
limit on how much memory you may lock. Trying to
allocate more than that would fail, so be sure you
set the limit correctly for the user you started
the daemon with (not for -u <username> user;
under sh this is done with 'ulimit -S -l NUM_KB').
-v verbose (print errors/warnings while in event loop)
-vv very verbose (also print client commands/reponses)
-h print this help and exit
-i print memcached and libevent license
-P <file> save PID in <file>, only used with -d option
-f <factor> chunk size growth factor, default 1.25
-n <bytes> minimum space allocated for key+value+flags, default 48
-R Maximum number of requests per event
limits the number of requests process for a given con nection
to prevent starvation. default 20
-b Set the backlog queue limit (default 1024)
-x <ip_addr> hostname or IP address of peer repcached
-X <num> TCP port number for replication (default: 11212)
[root@master01 ~]#
啟動memcached
提示：通過 repcached 安裝的 memcached 命令啟動 memcache 服務並實現 memcache 主備結構，其中-x 為對方即主 memcache 的 IP，-X 為本地啟動的用資料同步的埠;
在master02上編譯安裝repcached的過程同master01上一樣的；如果你不想那麼麻煩的再去編譯可以把master01上編譯好的二進位制檔案拷到master02上執行也是可以的
從master01上拷貝二進位制檔案到master02上
[root@master01 ~]# scp -r /usr/local/repcached/ master02:/usr/local/ memcached.1 100% 4290 1.9MB/s 00:00 memcached 100% 228KB 4.9MB/s 00:00 memcached-debug 100% 242KB 4.9MB/s 00:00 [root@master01 ~]#
在master02上啟動memcached
[root@master02 ~]# /usr/local/repcached/bin/memcached -d -m 2048 -p 11211 -u root -c 2048 -x 192.168.16.196 -X 52113 /usr/local/repcached/bin/memcached: error while loading shared libraries: libevent-2.0.so.5: cannot open shared object file: No such file or directory [root@master02 ~]#
提示：上述報錯主要原因上沒有安裝libevent-devel，所以在執行memcached時載入共享動態庫檔案找不到，解決辦法安裝libevent-devel即可
在master02上安裝依賴包libevent-devel
[root@master02 ~]# yum install -y libevent-devel
再次啟動memcached
提示：在master02上指定master01上的用於複製監聽埠，如果master02連線上master01，那麼在master02和master01上就不會在監聽我們手動指定的用於複製的埠；如果你在master02上還能夠看到手動指定的複製埠，說明master01和master02沒有建立連線；
驗證：往master01上寫入資料看看是否能夠同步到master02上呢？
提示：可以看到在master01上寫資料，在master02上是能夠正常讀取到的；
驗證在master02上寫資料，master01上是否可讀取呢？
提示：可以看到在master02上寫資料，也能夠及時的同步到master01上；到此基於repcached雙主模型的memcached就搭建好了，我們不管往那個master上寫入資料，它都會立刻同步資料到對方到memcached中去；