调优的过程中一般是两种调优
一种是响应时间的调优
一种是吞吐量调优
二者之中鱼与熊掌不可兼得
调优必备技能 一方面是硬件 另一方面是软件，二者知识结合才能更好的进行调优工作
量化系统指标，并设置一个正常的指标。
分三层调优，业务层调优-》应用层调优-》内核层调优 调优的效果会越来越不明显
应担优先思考业务是否能够进行调整，后思考应用层的调整，最后最后才考虑内核级别调优
不需要的东西可以优先关闭
CPU 相关
查看有多少CPU
[root@localhost ~]# cat /proc/cpuinfo
processor: 0
vendor_id: GenuineIntel
cpu family: 15
model : 4
model name: Intel(R) Xeon(TM) CPU 3.00GHz
stepping: 3
cpu MHz : 3000.110
cache size: 2048 KB
physical id: 0
siblings: 2
core id : 0
cpu cores: 1
apicid : 0
initial apicid: 0
fpu : yes
fpu_exception: yes
cpuid level: 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall lm constant_tsc pebs bts pni dtes64 monitor ds_cpl cid cx16 xtpr
bogomips: 6000.22
clflush size: 64
cache_alignment: 128
address sizes: 36 bits physical, 48 bits virtual
power management:
#篇幅有限 省略部分
查看缓存
[root@localhost ~]# lscpu
Architecture: x86_64 #CPU架构
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 4 #数量
On-line CPU(s) list: 0-3
Thread(s) per core: 2 #每个核线程数 如果为1代表不支持超线程
Core(s) per socket: 1 #一个物理CPU里面有几个核
Socket(s): 2
NUMA node(s): 1 #不支持numa的话就显示为1
Vendor ID: GenuineIntel
CPU family: 15
Model: 4
Stepping: 3
CPU MHz: 3000.110
BogoMIPS: 5999.18
L1d cache: 16K #一级数据缓存 L1i cache: 16K代表数据指令缓存
L2 cache: 2048K #二级缓存
NUMA node0 CPU(s): 0-3
[root@localhost ~]# lscpu -p
# The following is the parsable format, which can be fed to other
# programs. Each different item in every column has an unique ID
# starting from zero.
# CPU,Core,Socket,Node,,L1d,L2
0,0,0,0,,0,0
1,1,1,0,,1,1
2,0,0,0,,0,0
3,1,1,0,,1,1
物理CPU多颗的时候应该是怎么联系的？
内存
[root@localhost ~]# free -m
total used free shared buffers cached
Mem: 2887 2197 689 0 227 1097
-/+ buffers/cache: 872 2014
Swap: 4095 81 4014
[root@localhost ~]# cat /proc/meminfo
MemTotal: 2956360 kB
MemFree: 705444 kB
Buffers: 233004 kB
Cached: 1124116 kB
SwapCached: 4676 kB
Active: 1185600 kB
Inactive: 903772 kB
Active(anon): 554292 kB
Inactive(anon): 314724 kB
Active(file): 631308 kB
Inactive(file): 589048 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 4194296 kB
SwapFree: 4110580 kB
Dirty: 180 kB
Writeback: 0 kB
AnonPages: 731272 kB
Mapped: 97284 kB
Shmem: 136764 kB
Slab: 103268 kB
SReclaimable: 74584 kB
SUnreclaim: 28684 kB
KernelStack: 1408 kB
PageTables: 17276 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 5672476 kB
Committed_AS: 1578500 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 19940 kB
VmallocChunk: 34359706024 kB
HardwareCorrupted: 0 kB
AnonHugePages: 221184 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 7988 kB
DirectMap2M: 3137536 kB
两个指标
第几代技术
延迟
存储
机械磁盘
SSD (固态
RAID 技术 软 硬 RAID
接口技术 SATA SAS IDE
dmesg 启动的所有信息 启动之后还可以改变
/var/log/dmesg 启动的所有信息 启动完成后不会改变
lscpu
lscpu -p
getconf -a
x86info
dmidecode
lspci 查询pci信息
ethtool eth0 查询网卡信息
powertop 查询最近哪些进程最费电
sosreport 收集计算机信息，红帽工程师在需要提供帮助的时候会希望你提供这个命令生成的文件信息
本文转自 拖鞋崽 51CTO博客，原文链接:http://blog.51cto.com/1992mrwang/1398939
