theoforce 发表于 2015-11-22 14:24:27

Cacti监控MySQL实现过程中碰到的问题解汇总

  前言:cacti监控mysql服务器的大概50张graphs都弄出来了,也出图了,其中遇到一些问题,印象比较深刻的记录如下:
(一):添加io监控


  点击Create Graphs for this Host 进去创建IO的图,结果报错

  This data query returned 0 rows, perhaps there was a problem executing this data query. You can run this data query in debug mode to get more information.
  

  进入*Turn On Graph Debug Mode模式,报错如下:
RRDTool Command:
/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title='db-m2-slave-1 - Traffic' \
--rigid \
--base=1000 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit='0' \
--vertical-label='bits per second' \
--slope-mode \
--font TITLE:10: \
--font AXIS:7: \
--font LEGEND:8: \
--font UNIT:7: \
CDEF:cdefa='a,8,*' \
AREA:cdefa#00CF00FF:'Inbound'\
GPRINT:cdefa:LAST:' Current\:%8.2lf %s'\
GPRINT:cdefa:AVERAGE:'Average\:%8.2lf %s'\
GPRINT:cdefa:MAX:'Maximum\:%8.2lf %s\n'\
LINE1:cdefa#002A97FF:'Outbound'\
GPRINT:cdefa:LAST:'Current\:%8.2lf %s'\
GPRINT:cdefa:AVERAGE:'Average\:%8.2lf %s'\
GPRINT:cdefa:MAX:'Maximum\:%8.2lf %s\n'
RRDTool Says:
ERROR: invalid rpn expression in: a,8,*,如下图所示

  
  编辑linux主机下的/etc/snmp/snmpd.conf文件
找到:com2sec notConfigUserdefault       public
修改成:com2sec notConfigUserall       public
找到:accessnotConfigGroup ""      any       noauth    exactsystemview none none
修改成:accessnotConfigGroup ""      any       noauth    exactall none none
找到:#view all    included.1   80把该行的#去掉,
找到:#view mib2   included.iso.org.dod.internet.mgmt.mib-2 fc 把改行的#去掉,
重起snmpd:/etc/init.d/snmpd restart
  

  (二):MySQL添加主机出不来图
  # service httpd restart
  停止 httpd:                                             [确定]
  正在启动 httpd:httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName
  [确定]
  1)进入配置文件目录
  cd/etc/httpd/conf/
  2)编辑httpd.conf文件,搜索"#ServerName",添加ServerName localhost:80
# ls
extrahttpd.confmagicmime.typesoriginal
# vi httpd.conf
#ServerName www.example.com:80
ServerName localhost:80
3)再重新启动apache 即可。
  
  (三):启动报错
  # tail -f /var/log/httpd/error_log
   caught SIGTERM, shutting down
   SELinux policy enabled; httpd running as context unconfined_u:system_r:httpd_t:s0
   suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
   Digest: generating secret for digest authentication ...
   Digest: done
   Apache/2.2.15 (Unix) DAV/2 PHP/5.3.3 configured -- resuming normal operations
  解决方法:直接关闭SELinux以及防火墙

  

  (四):MySQL监控项出图报错
   PHP Fatal error:Allowed memory size of 134217728 bytes exhausted (tried to allocate 523800 bytes) in /var/www/html/cacti/lib/adodb/adodb.inc.php on line 833
  需要导入cacti.sql文件
  mysql -u root -p cacti < /var/www/html/cacti/cacti.sql
  
  (五):SNMP – Interface Statistics报错
  创建SNMP – Interface Statistics报错,如下:
  Created graph: db-m2-slave-2 - Traffic - |query_ifName|
  ERROR: no Data Source associated. Check Template
  # snmpwalk -c public -v 2c 10.254.3.73 ifHCInOctets
  IF-MIB::ifHCInOctets = No more variables left in this MIB View (It is past the end of the MIB tree)
  #
  # snmpwalk -c public -v 2c 10.254.3.73 if
  IF-MIB::ifTable = No Such Object available on this agent at this OID
  于是再次修改snmpd.conf,并重启snmpd
access   notConfigGroup &quot;&quot;       any       noauth   exact   systemview none none-->
access   notConfigGroup &quot;&quot;       any       noauth   exact   all   none none
  # service snmpd restart
  停止 snmpd:                                             [确定]
  正在启动 snmpd:                                           [确定]
  #
  # snmpwalk -c public -v 2c 10.254.3.73 if
  IF-MIB::ifTable = No more variables left in this MIB View (It is past the end of the MIB tree)
  【】解决
  在snmpd.conf配置文件里面,查找以下字段:
  ##         incl/excl subtree                        mask
  #view all    included.1                               80
  将该行前面的&quot;#&quot;去掉.
  之后重启snmpd服务解决。
  
  报错(六):
  移除出错的图

  

  进去Consoleà Graph Management àHost(选择出错的主机地址)—>Search(搜索报错的关键字Used Space),就会找到报错不出错的Graph Title栏目,勾选右侧的全选框,点击Go按钮删除掉这些无效的图即可,如下图所示:

  然后在新出来的提示界面,点击Continue按钮,删除。

  
  (七):Memory Free值为nan

  分析:memery free 无数据,原因: rrdtool的内存上限为10G。
  # find / -name *mem*.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_mem_buffers_189.rrd
  /var/www/html/cacti/rra/db-master-2_mem_free_156.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_lock_system_memory_20.rrd
  /var/www/html/cacti/rra/db-m2-slave-2_total_mem_alloc_74.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_total_mem_alloc_23.rrd
  /var/www/html/cacti/rra/db-m2-slave-2_lock_system_memory_71.rrd
  /var/www/html/cacti/rra/localhost_mem_swap_4.rrd
  /var/www/html/cacti/rra/db-master-2_total_mem_alloc_117.rrd
  /var/www/html/cacti/rra/db-master-2_mem_cache_155.rrd
  /var/www/html/cacti/rra/db-master-2_mem_buffers_154.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_mem_free_191.rrd
  /var/www/html/cacti/rra/localhost_mem_buffers_3.rrd
  /var/www/html/cacti/rra/db-m2-slave-2_mem_free_164.rrd
  /var/www/html/cacti/rra/db-m2-slave-2_mem_buffers_162.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_mem_buffers_54.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_mem_swap_55.rrd
  /var/www/html/cacti/rra/db-master-2_lock_system_memory_114.rrd
  /var/www/html/cacti/rra/db-m2-slave-2_mem_cache_163.rrd
  /var/www/html/cacti/rra/db-m2-slave-1_mem_cache_190.rrd
  /var/www/html/cacti/rra/db-master-2_mem_free_146.rrd
  #
  # rrdtool info /var/www/html/cacti/rra/db-m2-slave-1_mem_free_191.rrd |grep mem_free
  filename = &quot;/var/www/html/cacti/rra/db-m2-slave-1_mem_free_191.rrd&quot;
  ds.type = &quot;GAUGE&quot;
  ds.minimal_heartbeat = 120
  ds.min = 0.0000000000e+00
  ds.max = 1.0000000000e+07
  ds.last_ds = &quot;34166500&quot;
  ds.value = NaN
  ds.unknown_sec = 2
  #
  注:ds.max = 1.0000000000e+07数据的最大值设置为10G
  查看rrdtool如何进行修改,执行—help查看:
  # rrdtool --help
  RRDtool 1.3.8Copyright 1997-2009 by Tobias Oetiker <tobi@oetiker.ch>
  Compiled Aug 21 2010 10:57:18
  Usage: rrdtool command command_options
  Valid commands: create, update, updatev, graph, graphv,dump, restore,
  last, lastupdate, first, info, fetch, tune,
  resize, xport
  RRDtool is distributed under the Terms of the GNU General
  Public License Version 2. (www.gnu.org/copyleft/gpl.html)
  For more information read the RRD manpages
  #
  采用tune命令参数进行修改:
  # rrdtool tune *_mem_free_*.rrd mem_free:100000000
  DS typ: GAUGE   hbt: 120   min: 0.0000      max: 10000000.0000
  #
  有提示信息,表名tune失败,原来少了个-a参数,重新修改如下:
  # rrdtool tune *_mem_cache_*.rrd -a mem_cache:3000000000
  # rrdtool tune *_mem_free_*.rrd -a mem_free:3000000000
  # rrdtool tune *_mem_buffers_*.rrd -a mem_buffers:3000000000
  #
  这里发现rrdtool执行之后,只有一个host主机的的nan变成数字,其他主机的都没有变, 之所以如此是因为rrdtool tune * -a …命令只有一个.rrd文件起作用,其余的需要自己手动再一次次执行rrdtool tune命令。
  为了简化操作,特意写了一个ssh脚本如下:
  
vim /root/rrdtool_increate_mem.sh
cd /var/www/html/cacti/rra
ls *_mem_free_*.rrd -1 >a_mem_free.txt
for i in `cat a_mem_free.txt`
do
rrdtool tune $i -a mem_free:300000000;
done;
ls *_mem_cache_*.rrd -1 >a_mem_cache.txt
for i in `cat a_mem_cache.txt`
do
rrdtool tune $i -a mem_cache:300000000;
done;
ls *_mem_buffers_*.rrd -1 >a_mem_buffers.txt
for i in `cat a_mem_buffers.txt`
do
rrdtool tune $i -a mem_buffers:300000000;
done;  
  直接sh /root/rrdtool_increate_mem.sh即可。
  
【补充】
  调试cacti的graph,步骤如下:
  (1)   Console ,再进入Graph Manager ,再进入,选择对于的Host,搜索Memory,选中你要的图,点击链接,比如我这里是Memory Usage,如下图所示:

  
  (2)   再 点击Memory Usage链接进去,点击右上角的Debug模式:

  
  (3)   就会看到如下的debug界面,可以慢慢来观察RRDTool Command命令,为何是-nan值。

  
  
  (八):双网卡 Traffic 网卡流量问题
  如下图,em1和em2全部指向一个ip地址,只是em1不生效,em2生效了,但是ip地址在em1上,没有显示在em2一栏。

  所以,在graph图上,就没有数据,全为-nan-值,如下所示:

  在cacti服务器上面执行check:
  # snmpwalk -v 2c -c public 10.254.3.72 IF-MIB::ifDescr
  IF-MIB::ifDescr.1 = STRING: lo
  IF-MIB::ifDescr.2 = STRING: em1
  IF-MIB::ifDescr.3 = STRING: em2
  IF-MIB::ifDescr.4 = STRING: em3
  IF-MIB::ifDescr.5 = STRING: em4
  #
  确实有4个网卡信息记录,这些都没事,正常,经过仔细排查发现主要原因在下拉选框里面要选择Interface – Traffic (bits/sec),不要选择Interface – Traffic (bytes/sec),如下图所示:

  
  当选择了Interface – Traffic (bits/sec)之后graph就会出数据,有效果图了。

  
  

  (九):InnoDB Active/Locked Transactions
RRDTool Says:
ERROR: opening '/var/www/html/cacti/rra/db-m1-slave-1_locked_transactions_215.rrd': No such file or directory
  
  原因是mysql服务器上的让cacti访问的mysql数据库账号没有创建,创建mysql账号好,问题解决。
  
  (十):Tomcat - Connection Rate
  
RRDTool Says:
ERROR: invalid y-grid format
  依次进入Console -->Graph templates->Tomcat - Connection Rate->Unit Grid Value (--unit/--y-grid)
默认的值为1改成为0即可。

  



  
  
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