台州做网站seo,wordpress活动,嘉兴本地推广网站,销售平台网站建设方案一、NoSQL介绍
NoSQL是对 Not Only SQL、非传统关系型数据库的统称。
NoSQL一词诞生于1998年#xff0c;2009年这个词汇被再次提出指非关系型、分布式、不提供ACID的数据库设计模式。
随着互联网时代的到来#xff0c;数据爆发式增长#xff0c;数据库技术发展日新月异2009年这个词汇被再次提出指非关系型、分布式、不提供ACID的数据库设计模式。
随着互联网时代的到来数据爆发式增长数据库技术发展日新月异要适应新的业务需求。
而随着移动互联网、物联网的到来大数据的技术中NoSQL也同样重要。 数据库排名https://db-engines.com/en/ranking NOSQL分类 Key-value Store k/v数据库 性能好 O(1) , 如: redis、memcached Document Store 文档数据库 mongodb、CouchDB Column Store 列存数据库Column-Oriented DB HBase、Cassandra大数据领域应用广泛 Graph DB 图数据库 Neo4j Time Series 时序数据库 InfluxDB、Prometheus
二、Memcached
1、Memcached介绍 Memcached 只支持能序列化的数据类型不支持持久化基于Key-Value的内存缓存系统
memcached 虽然没有像redis所具备的数据持久化功能比如RDB和AOF都没有但是可以通过做集群同步的方式让各memcached服务器的数据进行同步从而实现数据的一致性即保证各memcached的数据是一样的即使有任何一台 memcached 发生故障只要集群中有一台 memcached 可用就不会出现数据丢失当其他memcached 重新加入到集群的时候,可以自动从有数据的memcached 当中自动获取数据并提供服务
Memcached 借助了操作系统的 libevent 工具做高效的读写。libevent是个程序库它将Linux的epoll、BSD类操作系统的kqueue等事件处理功能封装成统一的接口。即使对服务器的连接数增加也能发挥高性能。memcached使用这个libevent库因此能在Linux、BSD、Solaris等操作系统上发挥其高性能
Memcached 支持最大的内存存储对象为1M超过1M的数据可以使用客户端压缩或拆分报包放到多个key中比较大的数据在进行读取的时候需要消耗的时间比较长memcached 最适合保存用户的session实现session共享
Memcached存储数据时, Memcached会去申请1MB的内存, 把该块内存称为一个slab, 也称为一个page
Memcached 支持多种开发语言包括JAVA,C,Python,PHP,C#,Ruby,Perl等
Memcached 官网http://memcached.org/
2、Memcached 和 Redis 比较
比较类别Redismemcached支持的数据结构哈希、列表、集合、有序集合纯kev-value持久化支持有无高可用支持redis支持集群功能可以实现主动复制读写分离官方也提供了sentinel集群管理工具能够实现主从服务监控故障自动转移这一切对于客户端都是透明的无需程序改动也无需人工介入需要二次开发存储value容量最大512M最大1M内存分配临时申请空间可能导致碎片预分配内存池的方式管理内存能够省去内存分配时间虚拟内存使用有自己的VM机制理论上能够存储比物理内存更多的数据当数据超量时会引发swap把冷数据刷到磁盘上所有的数据存储在物理内存里网络类型非阻塞IO复用模型,提供一些非KV存储之外的排序聚合功能在执行这些功能时复杂的CPU计算会阻塞整个IO调度非阻塞IO复用模型水平扩展支持redis cluster 可以横向扩展暂无多线程Redis6.0之前是只支持单线程Memcached支持多线程,CPU利用方面Memcache优于redis单机QPS约10W约60W源代码可读性代码清爽简洁可能是考虑了太多的扩展性多系统的兼容性代码不清爽适用场景复杂数据结构、有持久化、高可用需求、value存储内容较大纯KV数据量非常大并发量非常大的业务
3、Memcached工作机制
1.内存分配机制
应用程序运行需要使用内存存储数据但对于一个缓存系统来说申请内存、释放内存将十分频繁非常容易导致大量内存碎片最后导致无连续可用内存可用。
Memcached采用了Slab Allocator机制来分配、管理内存。 Page分配给Slab的内存空间默认为1MB分配后就得到一个Slab。Slab分配之后内存按照固定字节大小等分成chunk。 Chunk用于缓存记录k/v值的内存空间。Memcached会根据数据大小选择存到哪一个chunk中假设chunk有128bytes、64bytes等多种数据只有100bytes存储在128bytes中存在少许浪费。 Chunk最大就是Page的大小即一个Page中就一个Chunk Slab ClassSlab按照Chunk的大小分组就组成不同的Slab Class, 第一个Chunk大小为 96B的Slab为Class1,Chunk 120B为Class 2,如果有100bytes要存那么Memcached会选择下图中Slab Class 2 存储因为它是120bytes的Chunk。Slab之间的差异可以使用Growth Factor 控制默认1.25。 根据数据大小分配到合适的盒子里 查看 Slab Class
[rootlocalhost ~]#memcached -u memcached -f 2 -vv
slab class 1: chunk size 96 perslab 10922
slab class 2: chunk size 192 perslab 5461
slab class 3: chunk size 384 perslab 2730
slab class 4: chunk size 768 perslab 1365
slab class 5: chunk size 1536 perslab 682
slab class 6: chunk size 3072 perslab 341
slab class 7: chunk size 6144 perslab 170
slab class 8: chunk size 12288 perslab 85
slab class 9: chunk size 24576 perslab 42
slab class 10: chunk size 49152 perslab 21
slab class 11: chunk size 98304 perslab 10
slab class 12: chunk size 196608 perslab 5
slab class 13: chunk size 393216 perslab 2
slab class 14: chunk size 1048576 perslab 1
26 server listening (auto-negotiate)
27 server listening (auto-negotiate)
28 send buffer was 212992, now 268435456
29 send buffer was 212992, now 268435456
28 server listening (udp)
29 server listening (udp)
2.懒过期Lazy Expiration
memcached不会监视数据是否过期而是在取数据时才看是否过期如果过期,把数据有效期限标识为0并不清除该数据。以后可以覆盖该位置存储其它数据。
3. LRU 最近最少使用算法
当内存不足时memcached会使用LRULeast Recently Used机制来查找可用空间分配给新记录使用
4.集群
Memcached集群称为基于客户端的分布式集群即由客户端实现集群功能即Memcached本身不支持集群
Memcached集群内部并不互相通信一切都需要客户端连接到Memcached服务器后自行组织这些节点并决定数据存储的节点。 注意Memcache不支持集群 4、Memcached安装和启动
官方安装说明 https://github.com/memcached/memcached/wiki/Install
1.yum安装
[rootlocalhost ~]#yum info memcached ##yum源的Memcached版本信息
已加载插件fastestmirror, langpacks
Loading mirror speeds from cached hostfile* base: mirrors.nju.edu.cn* extras: mirrors.nju.edu.cn* updates: mirrors.nju.edu.cn
可安装的软件包
名称 memcached
架构 x86_64
版本 1.4.15
发布 10.el7_3.1
大小 85 k
源 base/7/x86_64
简介 High Performance, Distributed Memory Object Cache
网址 http://www.memcached.org/
协议 BSD
描述 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. [rootlocalhost ~]#yum install memcached -y ###yum安装memcached[rootlocalhost ~]#rpm -ql memcached
/etc/sysconfig/memcached ###主配置文件
/usr/bin/memcached ###主进程
/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 [rootlocalhost ~]#vim /etc/sysconfig/memcached
PORT11211 #监听端口
USERmemcached #启动用户
MAXCONN1024 #最大连接数
CACHESIZE64 #最大使用内存
OPTIONS #其他选项监听所有 [rootlocalhost ~]#id memcached
uid990(memcached) gid985(memcached) 组985(memcached)
#安装Memcache服务后 会自动新建一个用户 [rootlocalhost ~]#systemctl start memcached.service ##开启服务[rootlocalhost ~]#ss -natl ###查看监听端口[rootlocalhost ~]#ss -natul ###查看监听端口协议
#Memcache服务使用的是TCP协议 [rootlocalhost ~]#yum install telnet -y 2.编译安装Memcached
[rootlocalhost ~]#yum -y install gcc libevent-devel ###安装依赖包[rootlocalhost ~]#cd /data[rootlocalhost data]#wget http://memcached.org/files/memcached-1.6.6.tar.gz ###下载安装包[rootlocalhost data]#tar xf memcached-1.6.6.tar.gz ###解压[rootlocalhost data]#cd memcached-1.6.6/[rootlocalhost memcached-1.6.6]#ls[rootlocalhost memcached-1.6.6]#./configure --prefix/apps/memcached[rootlocalhost memcached-1.6.6]#make make install[rootlocalhost memcached-1.6.6]#ls /apps/memcached/[rootlocalhost memcached-1.6.6]#ln -s /apps/memcached/bin/memcached /usr/bin/[rootlocalhost memcached-1.6.6]#useradd -r -s /sbin/nologin memcached[rootlocalhost memcached-1.6.6]#vim /etc/sysconfig/memcached
PORT11211
USERmemcached
MAXCONN1024
CACHESIZE64
OPTIONS #准备service文件
[rootcentos7 ~]#cat /lib/systemd/system/memcached.service eof
[Unit]
Descriptionmemcached daemon
Beforehttpd.service
Afternetwork.target
[Service]
EnvironmentFile/etc/sysconfig/memcached
ExecStart/apps/memcached/bin/memcached -p \${PORT} -u \${USER} -m \${CACHESIZE} -c \${MAXCONN} \$OPTIONS
[Install]
WantedBymulti-user.target
eof [rootlocalhost memcached-1.6.6]#systemctl daemon-reload
[rootlocalhost memcached-1.6.6]#systemctl start memcached.service
[rootlocalhost memcached-1.6.6]#systemctl status memcached.service 增长因子的改变 #默认前台执行
[rootcentos7 ~]#memcached -u memcached -m 1024 -c 65536 -f 2 -vv #以台方式执行
[rootcentos7 ~]#memcached -u memcached -m 1024 -c 65536 -d 3.Memcached启动程序说明
memcached常见的选项
[rootlocalhost memcached-1.6.6]#memcached -h
memcached 1.6.6
-p, --portnum TCP port to listen on (default: 11211)
-U, --udp-portnum UDP port to listen on (default: 0, off)
-s, --unix-socketfile UNIX socket to listen on (disables network support)
-a, --unix-maskmask access mask for UNIX socket, in octal (default: 700)
-A, --enable-shutdown enable ascii shutdown command
-l, --listenaddr interface to listen on (default: INADDR_ANY)
-d, --daemon run as a daemon
-r, --enable-coredumps maximize core file limit
-u, --useruser assume identity of username (only when run as root)
-m, --memory-limitnum item memory in megabytes (default: 64)
-M, --disable-evictions return error on memory exhausted instead of evicting
-c, --conn-limitnum max simultaneous connections (default: 1024)
-k, --lock-memory lock down all paged memory
-v, --verbose verbose (print errors/warnings while in event loop)
-vv very verbose (also print client commands/responses)
-vvv extremely verbose (internal state transitions)
-h, --help print this help and exit
-i, --license print memcached and libevent license
-V, --version print version and exit
-P, --pidfilefile save PID in file, only used with -d option
-f, --slab-growth-factornum chunk size growth factor (default: 1.25)
-n, --slab-min-sizebytes min space used for keyvalueflags (default: 48)
-L, --enable-largepages try to use large memory pages (if available)
-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 collectionis turned on automatically; if not, then it may be turned onby sending the stats detail on command to the server.
-t, --threadsnum number of threads to use (default: 4)
-R, --max-reqs-per-event maximum number of requests per event, limits therequests processed per connection to prevent starvation (default: 20)
-C, --disable-cas disable use of CAS
-b, --listen-backlognum set the backlog queue limit (default: 1024)
-B, --protocolname protocol - one of ascii, binary, or auto (default: auto-negotiate)
-I, --max-item-sizenum adjusts max item size(default: 1m, min: 1k, max: 1024m)
-F, --disable-flush-all disable flush_all command
-X, --disable-dumping disable stats cachedump and lru_crawler metadump
-W --disable-watch disable watch commands (live logging)
-Y, --auth-filefile (EXPERIMENTAL) enable ASCII protocol authentication. format:user:pass\nuser2:pass2\n
-e, --memory-filefile (EXPERIMENTAL) mmap a file for item memory.use only in ram disks or persistent memory mounts!enables restartable cache (stop with SIGUSR1)
-o, --extended comma separated list of extended optionsmost options have a no_ prefix to disable- maxconns_fast: immediately close new connections after limit (default: enabled)- hashpower: an integer multiplier for how large the hashtable should be. normally grows at runtime. (default starts at: 0)set based on STAT hash_power_level- tail_repair_time: time in seconds for how long to wait beforeforcefully killing LRU tail item.disabled by default; very dangerous option.- hash_algorithm: the hash table algorithmdefault is murmur3 hash. options: jenkins, murmur3- no_lru_crawler: disable LRU Crawler background thread.- lru_crawler_sleep: microseconds to sleep between itemsdefault is 100.- lru_crawler_tocrawl: max items to crawl per slab per rundefault is 0 (unlimited)- resp_obj_mem_limit: limit in megabytes for connection response objects.do not adjust unless you have high (100k) conn. limits.0 means unlimited (default: 0)- read_buf_mem_limit: limit in megabytes for connection read buffers.do not adjust unless you have high (100k) conn. limits.0 means unlimited (default: 0)- no_lru_maintainer: disable new LRU system background thread.- hot_lru_pct: pct of slab memory to reserve for hot lru.(requires lru_maintainer, default pct: 20)- warm_lru_pct: pct of slab memory to reserve for warm lru.(requires lru_maintainer, default pct: 40)- hot_max_factor: items idle cold lru age * drop from hot lru. (default: 0.20)- warm_max_factor: items idle cold lru age * this drop from warm. (default: 2.00)- temporary_ttl: TTLs below get separate LRU, cant be evicted.(requires lru_maintainer, default: 61)- idle_timeout: timeout for idle connections. (default: 0, no timeout)- slab_chunk_max: (EXPERIMENTAL) maximum slab size in kilobytes. use extreme care. (default: 512)- watcher_logbuf_size: size in kilobytes of per-watcher write buffer. (default: 256)- worker_logbuf_size: size in kilobytes of per-worker-thread bufferread by background thread, then written to watchers. (default: 64)- track_sizes: enable dynamic reports for stats sizes command.- no_hashexpand: disables hash table expansion (dangerous)- modern: enables options which will be default in future.currently: nothing- no_modern: uses defaults of previous major version (1.4.x)- External storage (ext_*) related options (see: https://memcached.org/extstore)- ext_path: file to write to for external storage.ie: ext_path/mnt/d1/extstore:1G- ext_page_size: size in megabytes of storage pages. (default: 64)- ext_wbuf_size: size in megabytes of page write buffers. (default: 4)- ext_threads: number of IO threads to run. (default: 1)- ext_item_size: store items larger than this (bytes, default 512)- ext_item_age: store items idle at least this long (seconds, default: no age limit)- ext_low_ttl: consider TTLs lower than this specially (default: 0)- ext_drop_unread: dont re-write unread values during compaction (default: disabled)- ext_recache_rate: recache an item every N accesses (default: 2000)- ext_compact_under: compact when fewer than this many free pages(default: 1/4th of the assigned storage)- ext_drop_under: drop COLD items when fewer than this many free pages(default: 1/4th of the assigned storage)- ext_max_frag: max page fragmentation to tolerate (default: 0.80)- slab_automove_freeratio: ratio of memory to hold free as buffer.(see doc/storage.txt for more info, default: 0.010) 修改memcached 运行参数可以使用下面的选项修改/etc/sysconfig/memcached文件 选项含义-uusername memcached运行的用户身份必须普通用户-p绑定的端口默认11211-mnum 最大内存单位MB默认64MB-cnum 最大连接数缺省1024-ddaemon 守护进程方式运行-f增长因子Growth Factor默认1.25-v详细信息-vv能看到详细信息-M使用内存直到耗尽不许LRU-U设置UDP监听端口0表示禁用UDP
5、使用memcached
1.memcached开发库和工具
与memcached通信的不同语言的连接器。libmemcached提供了C库和命令行工具。
#安装工具包
[rootlocalhost ~]#yum install libmemcached -y 1.Memping
[rootlocalhost ~]#memping --help
memping v1.0Ping a server to see if it is aliveCurrent options. A means the option takes a value.--version Display the version of the application and then exit.--help Display this message and then exit.--quiet stderr and stdin will be closed at application startup.--verbose Give more details on the progression of the application.--debug Provide output only useful for debugging.--serversList which servers you wish to connect to.--expireSet the expire option for the object.--binary Switch to binary protocol.--usernameUsername to use for SASL authentication--passwordPassword to use for SASL authentication [rootlocalhost memcached-1.6.6]#memping --servers 192.168.10.101
[rootlocalhost memcached-1.6.6]#echo $?
0 [rootlocalhost ~]#systemctl stop memcached.service [rootlocalhost memcached-1.6.6]#memping --servers 192.168.10.101
Failed to ping 192.168.10.101:11211 CONNECTION FAILURE
[rootlocalhost memcached-1.6.6]#echo $?
1 2.Memstat
[rootlocalhost ~]#memstat --servers 192.168.10.101
Server: 192.168.10.101 (11211)pid: 2643uptime: 52time: 1710430679version: 1.4.15libevent: 2.0.21-stablepointer_size: 64rusage_user: 0.000111rusage_system: 0.004910curr_connections: 10total_connections: 11connection_structures: 11reserved_fds: 20cmd_get: 0cmd_set: 0cmd_flush: 0cmd_touch: 0get_hits: 0get_misses: 0delete_misses: 0delete_hits: 0incr_misses: 0incr_hits: 0decr_misses: 0decr_hits: 0cas_misses: 0cas_hits: 0cas_badval: 0touch_hits: 0touch_misses: 0auth_cmds: 0auth_errors: 0bytes_read: 17bytes_written: 16limit_maxbytes: 67108864accepting_conns: 1listen_disabled_num: 0threads: 4conn_yields: 0hash_power_level: 16hash_bytes: 524288hash_is_expanding: 0bytes: 0curr_items: 0total_items: 0expired_unfetched: 0evicted_unfetched: 0evictions: 0reclaimed: 0 2.Memcached操作命令
[rootlocalhost ~]#cat /usr/share/doc/memcached-1.4.15/protocol.txt
#操作命令帮助路径 五种基本 memcached 命令执行最简单的操作。这些命令和操作包括
setaddflushgetdelete 前三个命令是用于操作存储在Memcached中的键值的标准修改命令都使用如下语法 command key flags expiration time bytesvalue command set/add/replace
key key 用于查找缓存值flags 可以包括键值对的整型参数客户机使用它存储关于键值对的额外信息expiration time 在缓存中保存键值对的时间长度以秒为单位0 表示永远bytes 在缓存中存储的字节数value 存储的值始终位于第二行 add key flags exptime bytes 增加key过期时间为秒bytes为存储数据的字节数 [rootlocalhost ~]#telnet 192.168.10.101 11211
Trying 192.168.10.101...
Connected to 192.168.10.101.
Escape character is ^].
add class 1 0 4
kysw
STORED
get class
VALUE class 1 4
kysw
END
set class 1 0 4
kkyy
STORED
get class
VALUE class 1 4
kkyy
END
delete class
DELETED
get class
ENDadd name 1 20 3
cxk
STORED
stats items
#显示各个slab中item的数目和存储市场最后一次访问距离现在的秒数STAT items:1:number 1
STAT items:1:age 5
STAT items:1:evicted 0
STAT items:1:evicted_nonzero 0
STAT items:1:evicted_time 0
STAT items:1:outofmemory 0
STAT items:1:tailrepairs 0
STAT items:1:reclaimed 0
STAT items:1:expired_unfetched 0
STAT items:1:evicted_unfetched 0
ENDstats slabs
#显示各个slab的信息包括chunk的大小、数目、使用情况等STAT 1:chunk_size 96
STAT 1:chunks_per_page 10922
STAT 1:total_pages 1
STAT 1:total_chunks 10922
STAT 1:used_chunks 1
STAT 1:free_chunks 10921
STAT 1:free_chunks_end 0
STAT 1:mem_requested 72
STAT 1:get_hits 1
STAT 1:cmd_set 2
STAT 1:delete_hits 0
STAT 1:incr_hits 0
STAT 1:decr_hits 0
STAT 1:cas_hits 0
STAT 1:cas_badval 0
STAT 1:touch_hits 0
STAT active_slabs 1
STAT total_malloced 1048512
END [rootlocalhost ~]#telnet 192.168.10.101 11211
Trying 192.168.10.101...
Connected to 192.168.10.101.
Escape character is ^].
stats ###查看服务状态
STAT pid 2643
STAT uptime 885
STAT time 1710431512
STAT version 1.4.15
STAT libevent 2.0.21-stable
STAT pointer_size 64
STAT rusage_user 0.006363
STAT rusage_system 0.038180
STAT curr_connections 10
STAT total_connections 13
STAT connection_structures 11
STAT reserved_fds 20
STAT cmd_get 3
STAT cmd_set 2
STAT cmd_flush 0
STAT cmd_touch 0
STAT get_hits 2
STAT get_misses 1
STAT delete_misses 0
STAT delete_hits 1
STAT incr_misses 0
STAT incr_hits 0
STAT decr_misses 0
STAT decr_hits 0
STAT cas_misses 0
STAT cas_hits 0
STAT cas_badval 0
STAT touch_hits 0
STAT touch_misses 0
STAT auth_cmds 0
STAT auth_errors 0
STAT bytes_read 129
STAT bytes_written 1127
STAT limit_maxbytes 67108864
STAT accepting_conns 1
STAT listen_disabled_num 0
STAT threads 4
STAT conn_yields 0
STAT hash_power_level 16
STAT hash_bytes 524288
STAT hash_is_expanding 0
STAT bytes 0
STAT curr_items 0
STAT total_items 2
STAT expired_unfetched 0
STAT evicted_unfetched 0
STAT evictions 0
STAT reclaimed 0
END 1.add——添加数据
[rootlocalhost ~]#telnet 192.168.241.11 11211
Trying 192.168.241.11...
Connected to 192.168.241.11.
Escape character is ^].
add name 1 0 3
#添加 键名为name的键 flages标志位1 永不超时 3字节的内容
wyb
#具体数据内容
STORED
2.set——修改数据
set name 1 0 3
#修改键名为name的键 flages标志位1 永不超时 3字节长度
cxk
#修改的内容为cxk
STORED
3.get——调用数据
get name
#调用 键名为name的数据
VALUE name 1 3
#name数据的信息
cxk
#具体数据内容 此处由于set修改之后 所以显示的为set修改后的数据内容
END
4.delete——删除数据
get name
VALUE name 1 3
cxk
END
delete name
DELETED
get name
#删除之后再调用数据 显示为空
END
5.flush——清空数据
add name 1 0 3
cxk
STORED
add class 1 0 3
wyb
STORED
get name
VALUE name 1 3
cxk
END
get class
VALUE class 1 3
wyb
END
flush_all
OK
get name
END
get class
END
6、Memcached集群部署架构
1.基于Magent的部署架构
Magent是google开发的项目,应用端通过负载均衡服务器连接到magent然后再由magent代理用户应用请求到memcached处理底层的memcached为双主结构会自动同步数据本部署方式存在magent单点问题,因此需要两个magent做高可用。 项目站点https://code.google.com/archive/p/memagent/此项目过于陈旧,且不稳定,当前已经废弃 2.Repcached实现原理
项目站点http://repcached.sourceforge.net/ 在 master上可以通过 -X 选项指定 replication port(默认为11212/tcp)在 slave上通过 -x 指定复制的master并连接事实上如果同时指定了 -x/-X repcached先会尝试连接对端的master但如果连接失败它就会用 -X参数来自己 listen成为master如果 master坏掉 slave侦测到连接断了它会自动 listen而成为 master而如果 slave坏掉master也会侦测到连接断开它就会重新 listen等待新的 slave加入。
从这方案的技术实现来看其实它是一个单 master单 slave的方案但它的 master/slave都是可读写的而且可以相互同步所以从功能上看也可以认为它是双机 master-master方案
3.简化后的部署架构
magent已经有很长时间没有更新因此可以不再使用magent直接通过负载均衡连接到memcached仍然有两台memcached做高可用repcached版本的memcached之间会自动同步数据以保持数据一致性即使其中的一台memcached故障也不影响业务正常运行故障的memcached修复上线后再自动从另外一台同步数据即可保持数据一致性。 4.部署Repcached
[rootlocalhost ~]#yum -y install gcc libevent libevent-devel
#安装依赖环境
[rootlocalhost opt]#ls
[rootlocalhost opt]#wget https://jaist.dl.sourceforge.net/project/repcached/repcached/2.2.1-1.2.8/memcached-1.2.8-repcached-2.2.1.tar.gz
[rootlocalhost opt]#ls
memcached-1.2.8-repcached-2.2.1.tar.gz
[rootlocalhost opt]#tar xf memcached-1.2.8-repcached-2.2.1.tar.gz
[rootlocalhost opt]#cd memcached-1.2.8-repcached-2.2.1/
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#./configure --prefix/apps/repcached --enable-replication如果直接执行make会出现如下报错
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#make
make all-recursive
make[1]: 进入目录“/opt/memcached-1.2.8-repcached-2.2.1”
Making all in doc
make[2]: 进入目录“/opt/memcached-1.2.8-repcached-2.2.1/doc”
make[2]: 对“all”无需做任何事。
make[2]: 离开目录“/opt/memcached-1.2.8-repcached-2.2.1/doc”
make[2]: 进入目录“/opt/memcached-1.2.8-repcached-2.2.1”
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: 在函数‘add_iov’中:
memcached.c:697:30: 错误‘IOV_MAX’未声明(在此函数内第一次使用)if (m-msg_iovlen IOV_MAX ||^
memcached.c:697:30: 附注每个未声明的标识符在其出现的函数内只报告一次
make[2]: *** [memcached-memcached.o] 错误 1
make[2]: 离开目录“/opt/memcached-1.2.8-repcached-2.2.1”
make[1]: *** [all-recursive] 错误 1
make[1]: 离开目录“/opt/memcached-1.2.8-repcached-2.2.1”
make: *** [all] 错误 2解决办法是修改源码配置信息
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#ls
aclocal.m4 config.status Makefile.am scripts
assoc.c config.sub Makefile.in slabs.c
assoc.h configure memcached.c slabs.h
AUTHORS configure.ac memcached_dtrace.d stamp-h1
AUTHORS.repcached COPYING memcached_dtrace.h stats.c
ChangeLog daemon.c memcached.h stats.h
ChangeLog.repcached depcomp memcached.spec t
compile doc missing thread.c
config.guess install-sh NEWS TODO
config.h items.c README t.rep
config.h.in items.h replication.c
config.log Makefile replication.h
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#vim memcached.c
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#sed -n 56,59p memcached.c
#ifndef IOV_MAX
#if defined(__FreeBSD__) || defined(__APPLE__)
# define IOV_MAX 1024
#endif
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#sed -n 56,60p memcached.c
#ifndef IOV_MAX
#if defined(__FreeBSD__) || defined(__APPLE__)
# define IOV_MAX 1024
#endif
#endif
#需要将57和59行删除
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#vim memcached.c
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#sed -n 56,58p memcached.c
#ifndef IOV_MAX
# define IOV_MAX 1024
#endif
#最终56-60行留下这些内容即可
再次编译[rootlocalhost memcached-1.2.8-repcached-2.2.1]#make make install
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#ln -s /apps/repcached/bin/memcached /usr/bin/
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#useradd -r -s /sbin/nologin memcached
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#memcached -d -m 1024 -p 11211 -u memcached -c 2048 -x 192.168.241.22
#-x 192.168.241.22 为远端的192.168.241.22 后台启动
[rootlocalhost memcached-1.2.8-repcached-2.2.1]#ss -ntlap|grep 11211
LISTEN 0 128 *:11211 *:* users:((memcached,pid4848,fd7))
LISTEN 0 128 :::11211 :::* users:((memcached,pid4848,fd8))
可以使用rsync远程拷贝命令将配置同步到远端
[rootlocalhost ~]#rsync -a /apps 192.168.10.101:/
The authenticity of host 192.168.10.101 (192.168.10.101) cant be established.
ECDSA key fingerprint is SHA256:CcASxxV4CvFA6w68th3aaCYGbGB3UwaAK1xifsM/Pk.
ECDSA key fingerprint is MD5:d6:ee:2e:4d:f6:34:c5:14:0e:ef:99:8c:54:48:c6:be.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 192.168.10.101 (ECDSA) to the list of known hosts.
root192.168.10.101s password:
[rootnode2 opt]#ls /
apps boot etc lib media opt root sbin sys usr
bin dev home lib64 mnt proc run srv tmp var
[rootnode2 opt]#ln -s /apps/repcached/bin/memcached /usr/bin/
[rootnode2 opt]#useradd -r -s /sbin/nologin memcached
[rootnode2 ~]#yum -y install gcc libevent libevent-devel
#安装依赖库
[rootnode2 opt]#memcached -d -m 1024 -p 11211 -u memcached -c 2048 -x 192.168.10.100
[rootnode2 opt]#ss -natpl|grep 11211
LISTEN 0 128 *:11211 *:* users:((memcached,pid4211,fd9))
LISTEN 0 128 :::11211 :::* users:((memcached,pid4211,fd10))
[rootnode2 opt]#yum install telnet -y
[rootnode2 opt]#telnet 192.168.10.100 11211
Trying 192.168.10.100...
Connected to 192.168.10.100.
Escape character is ^].
add name 1 0 3
cxk
STORED
quit
Connection closed by foreign host.
查看数据是否同步
[rootnode3 ~]#yum install telnet -y
[rootnode3 ~]#telnet 192.168.10.101 11211
Trying 192.168.10.101...
Connected to 192.168.10.101.
Escape character is ^].
get name
VALUE name 1 3
cxk
END
quit
Connection closed by foreign host.
[rootnode3 ~]#telnet 192.168.10.100 11211
Trying 192.168.10.100...
Connected to 192.168.10.100.
Escape character is ^].
get name
VALUE name 1 3
cxk
END
quit
Connection closed by foreign host.
5.使用HAproxy高可用部署
[rootnode3 ~]#yum install haproxy.x86_64 -y
[rootnode3 ~]#systemctl start haproxy.service
[rootnode3 ~]#systemctl status haproxy.service
● haproxy.service - HAProxy Load BalancerLoaded: loaded (/usr/lib/systemd/system/haproxy.service; disabled; vendor preset: disabled)Active: active (running) since 四 2024-03-14 14:22:43 CST; 4s agoMain PID: 37006 (haproxy-systemd)CGroup: /system.slice/haproxy.service├─37006 /usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haprox...├─37011 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/ha...└─37012 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/ha...3月 14 14:22:43 node3.node3 systemd[1]: Started HAProxy Load Balancer.
3月 14 14:22:43 node3.node3 systemd[1]: Starting HAProxy Load Balancer...
3月 14 14:22:44 node3.node3 haproxy-systemd-wrapper[37006]: haproxy-system...
Hint: Some lines were ellipsized, use -l to show in full.
[rootnode3 ~]#vim /etc/haproxy/haproxy.cfg
[rootnode3 ~]#sed -n 87,91p /etc/haproxy/haproxy.cfg
listen membind 192.168.10.102:11211mode tcpserver m1 192.168.10.100:11211 checkserver m2 192.168.10.101:11211 check
[rootnode3 ~]#systemctl restart haproxy.service
[rootnode3 ~]#systemctl status haproxy.service
● haproxy.service - HAProxy Load BalancerLoaded: loaded (/usr/lib/systemd/system/haproxy.service; disabled; vendor prActive: active (running) since 四 2024-03-14 14:40:37 CST; 2s agoMain PID: 37572 (haproxy-systemd)CGroup: /system.slice/haproxy.service├─37572 /usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haproxy.cf├─37574 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haprox└─37576 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haprox3月 14 14:40:37 node3.node3 systemd[1]: Started HAProxy Load Balancer.
3月 14 14:40:37 node3.node3 systemd[1]: Starting HAProxy Load Balancer...
3月 14 14:40:38 node3.node3 haproxy-systemd-wrapper[37572]: haproxy-systemd-wra
3月 14 14:40:38 node3.node3 haproxy-systemd-wrapper[37572]: [WARNING] 073/14403
3月 14 14:40:38 node3.node3 haproxy-systemd-wrapper[37572]: [WARNING] 073/14403
Hint: Some lines were ellipsized, use -l to show in full.
[rootnode3 ~]#ss -natpl|grep 11211
LISTEN 0 128 192.168.10.102:11211 *:* users:((haproxy,pid37576,fd7))
#此为HAproxy服务在代为监听
测试
[rootnode3 ~]#telnet 192.168.10.102 11211
Trying 192.168.10.102...
Connected to 192.168.10.102.
Escape character is ^].
get name
VALUE name 1 3
cxk
END
add class 1 0 3
wyb
STORED
quit
Connection closed by foreign host.
[rootnode2 opt]#telnet 192.168.10.101 11211
Trying 192.168.10.101...
Connected to 192.168.10.101.
Escape character is ^].
get name
VALUE name 1 3
cxk
END
get class
VALUE class 1 3
wyb
END
quit
Connection closed by foreign host.
