2009年12月29日
#
rsync -avz -e ssh bak@192.168.0.138:/home/res /home/res/bak
1. 使用Replication進行實時備份
參考mysql docs
2. 定期在slave上使用shell,mysqldump,sftp,crontab進行永久備份
#!/bin/sh
export d=`date +%Y%m%d%H%M%S`
mkdir -p /data/dbbak/baktables/$d
for i in `echo "show tables" | mysql -u bak -ppassword db|grep -v Tables`;
do
echo $i; mysqldump --add-drop-table --allow-keywords -q -a -c -u bak -ppasswod mbook_hd $i > backup/$d/$i.sql
done
tar czf backup/$d.tar.gz backup/$d/
rm -rf backup/$d/
lftp -e "cd /dbbak/; mput -c $d.tar.gz; quit" -u bak,password sftp://192.168.0.138
參考http://ocaoimh.ie/simple-mysql-backup/
10G級別的可以每天作一次備份，100G級別看帶寬和硬盤，T級沒有經驗
2009年2月19日
#
#!/usr/bin/env python
import string, os, sys
dir = '/home/waterye/works/'
files = os.listdir(dir)
for f in files:
if not os.path.isfile(dir+os.sep+f): continue
linecount = 0
fp = open(dir+os.sep+f,'r')
for line in fp:
linecount += 1
fp = open(dir+os.sep+f,'r')
for i,line in enumerate(fp):
if (i==linecount-1 and line.endswith('\n')):
print f
print "--------------------------------"
* bash太難理解，還是用py看上去舒服，雖然不專業，但能完成任務就行
2008年12月4日
#
"perldoc DateTime" would have told you how to format milliseconds.
use DateTime;
use Time::HiRes qw(time);
my $dt = DateTime->from_epoch( epoch => time() );
print $dt->strftime('%Y-%m-%d %H-%M-%S-%3N'), "\n";
* sudo apt-get install libdatetime-perl
perl真麻煩
2008年10月31日
#
1. http://www.whalin.com/memcached/ v2.0.1
2. http://code.google.com/p/spymemcached/ v2.2
a. 使用whalin版會導致File Descriptor leak,而使用spy版則不會，原因是whalin版沒有使用selector管理socketchannel.
Thread.sleep(1000 * 30);
System.out.println("begin
");
Selector selector = null;
SocketChannel channel = null;
try {
String host = "192.168.0.74";
int port = 11211;
int timeout = 1000 * 60;
selector = Selector.open();
channel = SocketChannel.open();
channel.configureBlocking(false);
channel.connect(new InetSocketAddress(host, port));
channel.register(selector, channel.validOps());
try {
selector.select();
} catch (IOException e) {
e.printStackTrace();
}
Iterator it = selector.selectedKeys().iterator();
int i = 0;
while (it.hasNext()) {
i++;
System.out.println(i);
SelectionKey selKey = (SelectionKey) it.next();
it.remove();
try {
processSelectionKey(selKey);
} catch (IOException e) {
e.printStackTrace();
selKey.cancel();
}
}
System.out.println("unclose");
Thread.sleep(1000 * 30);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (channel != null && channel.isOpen()) {
try {
channel.close();
} catch (Exception e) {
e.printStackTrace();
}
}
if (selector!=null) {
selector.close(); // not fd leak
}
}
System.out.println("end");
Thread.sleep(1000 * 30 * 1);
通過lsof -p pid | grep pipe可以觀察是否有fd leak.
b. w版set 1000000 object 需要600s左右，s版只需150s左右
2008年10月21日
#
192.168.0.74 [root avi]$ python /root/memcached/cacti-memcached-1.0/memcached.py localhost
total_items:2002344 get_hits:3 uptime:50291 cmd_get:3 time:1224521129 bytes:58888890 curr_connections:1 connection_structures:8 bytes_written:16167008 limit_maxbytes:402653184 cmd_set:2002344 curr_items:1000000 rusage_user:101.730357 get_misses:0 rusage_system:199.092442 bytes_read:63849044 total_connections:314
2008年10月5日
#
1. iftop
sudo apt-get install iftop
sudo iftop -i ppp0
2. slurm
sudo apt-get install slurm
slurm -i ppp0
3. vnstat
sudo apt-get install vnstat
sudo chmod o+x /usr/bin/vnstat
sudo chmod o+wx /var/lib/vnstat/
vnstat -u -i ppp0
vnstat -i ppp0
vnstat -l -i ppp0
因為不是server就沒有用復雜的mrtg
2008年9月28日
#
vi,gedit會在最后一行加上\n,實在找不到好的解決方法,只好自己寫個shell script刪掉
#!/usr/bin/env python
import sys
oldfile=sys.argv[1]
newfile=sys.argv[2]
print oldfile,newfile,
print
linecount = 0
str = ''
f = open(oldfile,'r')
for line in f:
linecount += 1
f = open(oldfile,'r')
for i,line in enumerate(f):
if (i==linecount-1):
str += line.replace('\n','')
# print line.replace('\n','')
else:
str += line
# print line,
#print len(str),str
f2 = open(newfile, 'w')
f2.write(str)
quit()
2008年9月24日
#
free -lmt
cat /proc/meminfo
dmesg |grep [mM][eE][mM]
cat /proc/pid/status
2008年9月22日
#
1. find . -type f -exec rm -v {} \;
2. nice -n 19 rm -rf directory
3. ls | xargs rm
4. find . -mtime +90 -type f -exec rm -v {} \;
采用第四種最好，把一些舊的文件先刪除