March 14, 2013 Exadata, oracle No comments Exadata
ASR XD报警抛出如下错误
" dm01cel02: Hardware Error has been detected in the Flash Logs on the Cell Node dm01cel02: Please open up a Service Request with Oracle to resolve the Error dm01cel02: View File /tmp/ASR-Flash-Fault-Check-Log for further Information of the Error dm01cel02: This log File c[......]
March 13, 2013 linux, system No comments linux tools
Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. It was designed to rapidly scan large networks, although it works fine against single hosts. While Nmap is commonly used for security audits, many systems and network administrators find it useful for routi[……]
March 8, 2013 mongodb, MYSQL, NoSQL, performance No comments test
对于业务的激活码需求做了一次关于mysql,mongodb的比对.mysql分为normal,key partition 数量分别是1亿和10亿数据,mysql采用直接访问PK键,partition key为PK,mysql table size 为90G,mongodb table size为157G。
[liuyang@yhdem ~]$ cat /proc/cpuinfo |grep processor |wc -l 24 [liuyang@yhdem ~]$ cat /etc/issue Oracle Linux Server release 5.8 Kerne[......]
March 5, 2013 linux, system No comments linux tools
February 28, 2013 linux, system No comments linux tools
pidstat是一款很不错的针对linux pid状态监控的程序
The pidstat command is used for monitoring individual tasks currently being managed by the Linux kernel.
It writes to standard output activities for every task selected with option -p or for every task managed by the Linux kernel if option -p ALL has been used.[……]
February 27, 2013 linux, system No comments linux tools
本来想写一篇关于nicstat的文章,霸爷已经写的非常好了参考这里nicstat 网络流量统计利器
这里说明一下使用nicstat 可以完美替代iptraf ,nload 等工具
同样可以替代watch –命令行模式:
eg:
Every 1.0s: /sbin/ifconfig eth0 | grep bytes Wed Feb[......]
February 27, 2013 linux, system No comments linux tools
Perf is a profiler tool for Linux 2.6+ based systems that abstracts away CPU hardware differences in Linux performance measurementsand presents a simple commandline interface. Perf is based on the perf_events interface exported by recent versions of the Linux kernel. This article demonstrates the pe[……]
February 17, 2013 Architect, network No comments life
+------------+----------+-------------+------------+-------------+-------------+ |bps |B/s |network |storage |port |bus | +------------+----------+-------------+------------+-------------+-------------+ |56/48K |5.6/4.8K |Modem 56k | |[......]
January 29, 2013 MYSQL, performance No comments mysql
mysql 数据库 poor IO performance.从DELL 815(6disk raid 5,oel5.5) 迁移至 HP DL380 (14disk raid 1+0,rhl5.8)
当时的IO 表现
avg-cpu: %user %nice %system %iowait %steal %idle
4.55 0.00 1.30 0.25 0.00 93.90
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq[......]
January 23, 2013 oracle, replication No comments internal
11g ADG 给了大家更多的灾备选择,包括之前美国飓风,给了ADG大放光彩的机会,但是ADG并没有想象中的那么完美,以下是最近的一个CASE,具体过程不详写了,目前这个case还在跟进中,记录之：
[oracle@dcb-srv-0174 trace]$ cat itemstd02_ora_22156.trc |grep "LibraryObjectLock" |awk '{print $3 "-- obj handle get"}' | uniq -c |awk '{ if ($1>100) print $[......]