Mac下配置Apache Httpd負載均衡(Load Balancer)之mod_jk
httpd版本: httpd-2.4.17
jk版本: tomcat-connectors-1.2.41
參考來源:
Apache (1) —— Mac下安裝Apache Httpd到自定義路徑（非/etc/apache2）
Apache (2) —— Mac 下安裝多個Apache Tomcat例項
How to Compile Tomcat mod_jk connector on Mac OS X Mavericks
Installing mod_jk for Apache 2.2 on Mac OS X 10.5 Leopard
Apache配置反向代理、負載均衡和叢集(mod_proxy方式)
準備
首先我們參照下面兩篇文章配置好httpd和兩個Tomcat例項
其中Tomcat的兩個例項node-a和node-b分別存放與"./servers/cluster/tomcat/node-a"和"/servers/cluster/tomcat/node-b"下
對應的配置分別為：
- Server Port: 8015 與 8025
- Connector: 8081 與 8082
- AJP: 8019 與 8029
另分別為連個例項新增jvmRoute的配置
node-a
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat1">node-b
<Engine name="Catalina" defaultHost="localhost" jvmRoute="tomcat2">
注意：不要忘記修改供測試的頁面特徵
配置httpd負載均衡（Load Balancer）
httpd負載均衡Tomcat的方式主要可以分為兩類
- httpd自帶的mod_proxy
- Tomcat提供了專門的JK外掛來負責Tomcat和HTTP伺服器的通訊mod_jk
*注意 本篇文章主要關注第二類配置
首先編譯
在Apache的網站上下載tomcat-connectors-1.2.41，然後解壓。
執行命令編譯
$ cd native
$ ./configure CFLAGS='-arch x86_64' APXSLDFLAGS='-arch x86_64' --with-apxs=/usr/sbin/apxs
$ make
$ sudo make install*注意 --with-apxs需要指向目標節點的apxs
此處我本地的路徑為
/Users/Richard/Documents/Dev/servers/cluster/httpd/node-a/bin/apxs如果執行正常不出錯，末尾幾行的輸出為
...
config.status: creating common/list.mk
config.status: creating common/jk_types.h
config.status: creating common/config.h
config.status: executing depfiles commands
config.status: executing libtool commands然後"./native"下執行make
期間會出現warning，可以暫時忽略不影響
jk_lb_worker.c:1397:36: warning: address of array
'p->worker->session_cookie_path' will always evaluate to 'true'
[-Wpointer-bool-conversion]
if (p->worker->session_cookie_path && *p->worker->se...
~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ ~~make執行正常的最後幾行輸出為
...
Making all in common
make[1]: Nothing to be done for `all'.
Making all in apache-2.0
make[1]: Nothing to be done for `all'.make install如果在非sudo狀態下，最後會出現錯誤
...
install: /Users/Richard/Documents/Dev/servers/cluster/httpd/node-a/modules/mod_jk.so: Permission denied
apxs:Error: Command failed with rc=4653056
.
make[1]: *** [install_dynamic] Error 1
make: *** [install-recursive] Error 1sudo執行make install
...
libtool: install: ranlib /Users/Richard/Documents/Dev/servers/cluster/httpd/node-a/modules/mod_jk.a
chmod 755 /Users/Richard/Documents/Dev/servers/cluster/httpd/node-a/modules/mod_jk.so
Please be sure to arrange /Users/Richard/Documents/Dev/servers/cluster/httpd/node-a/conf/httpd.conf...
make[2]: Nothing to be done for `install-exec-am'.
make[2]: Nothing to be done for `install-data-am'.配置mod_jk
在node-a下新建資料夾"other"，並建立檔案workers.properties
# Define two status worker:
# - jk-status for read-only use
# - jk-manager for read/write use
worker.list=jk-status
worker.jk-status.type=status
worker.jk-status.read_only=true
worker.list=jk-manager
worker.jk-manager.type=status
# We define a load balancer worker
# with name "balancer"
worker.list=balancer
worker.balancer.type=lb
worker.balancer.error_escalation_time=0
worker.balancer.max_reply_timeouts=10
worker.balancer.sticky_session=true
worker.balancer.sticky_session_force=true
# Now we add members to the load balancer First member is "tomcat1", most attributes are inherited from the template "worker.template".
worker.balancer.balance_workers=tomcat1
worker.tomcat1.reference=worker.template
worker.tomcat1.host=127.0.0.1
worker.tomcat1.port=8019
worker.tomcat1.activation=A
# Second member is "tomcat2", most attributes are inherited from the template "worker.template".
worker.balancer.balance_workers=tomcat2
worker.tomcat2.reference=worker.template
worker.tomcat2.host=127.0.0.1
worker.tomcat2.port=8029
worker.tomcat2.activation=A
# Finally we put the parameters
worker.template.type=ajp13
worker.template.socket_connect_timeout=5000
worker.template.socket_keepalive=true
worker.template.ping_mode=A
worker.template.ping_timeout=10000
worker.template.connection_pool_minsize=0
worker.template.connection_pool_timeout=600
worker.template.reply_timeout=300000
worker.template.recovery_options=3 *注意上面的host配置都是127.0.0.1，會影響我們下面的測試
並同時在"./node-a/other/"下建立檔案uriworkermap.properties
/*.do=balancer
/*.jsp=balancer
#/*.gif=balancer
#/*.jpg=balancer
#/*.png=balancer
#/*.css=balancer
#/*.js=balancer
#/*.htm=balancer
#/*.html=balancer
#/*.txt=balancer
# Optionally filter out all .jpeg files inside that context
# For no mapping the url has to start with exclamation (!)
!/servlets-examples/*.jpeg=lb
#
# Mount jkstatus to /jkmanager
# For production servers you will need to
# secure the access to the /jkmanager url
#
/jk-manager=jk-manager
/jk-status=jk-status 最後
為httpd.conf，新增配置
# 載入jk配置檔案
Include conf/mod_jk.conf 測試
重新啟動httpd，並用瀏覽器訪問"localhost:81"，提示"Service Unavailable"錯誤
檢視"./node-a/log"目錄下"mod_jk.log"檔案
[Wed Dec 09 15:00:31.403 2015] [13735:4417540096] [info] get_most_suitable_worker::jk_lb_worker.c (1119): all workers are in error state for session QUMQZVRPS1-4MX593EAOD71Y6YAFXUP1-U734UPHI-1
[Wed Dec 09 15:00:31.403 2015] [13735:4417540096] [info] service::jk_lb_worker.c (1664): All tomcat instances failed, no more workers left (attempt=1, retry=1)
[Wed Dec 09 15:00:31.403 2015] [13735:4417540096] [info] service::jk_lb_worker.c (1675): All tomcat instances are busy or in error state
[Wed Dec 09 15:00:31.403 2015] [13735:4417540096] [error] service::jk_lb_worker.c (1680): All tomcat instances failed, no more workers left
[Wed Dec 09 15:00:31.403 2015] [13735:4417540096] [info] jk_handler::mod_jk.c (2991): Service error=0 for worker=balancer嘗試訪問
127.0.0.1:81得到正常結果
這樣就完成一個以httpd單節點為負載均衡器分發到不同Tomcat的簡單架構。
*擴充套件
- 如果將host改為"localhost"是否能正常訪問?
- 與另一篇中用httpd自帶lb的方式不同對映的路徑（"./test"），這裡是根目錄，需要如何配置達到相同效果?
- 這裡測試結果可以正常顯示樣式和圖片，是什麼配置起的作用？