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Use ssh-copy-id avoid inputing password

ssh-copy-id 避免ssh輸入密碼的用法：

[root@hengtiandesk118 .ssh]# ssh-copy-id -i id_rsa.pub 10.1.186.51
10
Warning: Permanently added '10.1.186.51' (RSA) to the list of known hosts.
root@10.1.186.51's password:
Now try logging into the machine, with "ssh '10.1.186.51'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

[root@hengtiandesk118 .ssh]# ssh 10.1.186.51
Last login: Thu May 10 18:33:55 2012 from 10.5.4.201
[root@xen186v01 ~]#

這個腳本只要裝了openssh-clients就可以用了。

以前都是手動復制粘貼的...

posted @ 2012-05-11 09:58 Milo的海域閱讀(332) | 評論 (0) | 編輯收藏

幾個ssh管道用法

原來ssh可以這樣用

1. remote file copy

[root@xen74v01 ~]# cat test.pl
#!/usr/bin/perl
print "eth0.74"=~/(\w+)/;
print "\n";
[root@xen74v01 ~]# cat test.pl | ssh 10.1.74.76 'cat - > /tmp/test.pl'

拷貝文件時，如果文件很大，又不想影響網絡IO可以用pv工具進行流量控制

pv -L10m test.pl | ssh 10.1.74.76 'cat - > /tmp/test.pl'

這里pv的行為跟cat比較類似，但是支持IO流量控制，這里設置10M/s.

2. local script remote execute

[root@xen74v01 ~]# cat test.pl
#!/usr/bin/perl
print "eth0.74"=~/(\w+)/;
print "\n";
[root@xen74v01 ~]# perl test.pl
eth0
[root@xen74v01 ~]# cat test.pl | ssh 10.1.74.76 'perl'
eth0
[root@xen74v01 ~]# ssh 10.1.74.76 'perl' < test.pl
eth0

這樣就不用把腳本拷貝到遠端去執行了

參考：

http://linux.icydog.net/ssh/piping.php

http://www.ivarch.com/programs/quickref/pv.shtml

http://www.mysqlperformanceblog.com/2009/05/20/hint-throttling-xtrabackup/

posted @ 2012-05-09 17:13 Milo的海域閱讀(3199) | 評論 (0) | 編輯收藏

Notes for SNMP

1. Tutorial
http://net-snmp.sourceforge.net/wiki/index.php/Tutorials

2. Config & start agent
snmpconf

3. snmpwalk example

snmpwalk -v2c -c public 10.1.74.51

4. check MIB modules

snmptranslate -Dinit_mib .1.3 2>&1 |grep MIBDIR

5. extending MIB Module
http://net-snmp.sourceforge.net/wiki/index.php/TUT:Writing_a_MIB_Module
   a. download net-snmp src code
   b. MIB definition
   c. mib2c (in net-snmp-perl)
   d. make & make install
   e. edit snmpd conf & restart agent
   f. snmpwalk to verify

posted @ 2012-05-07 16:57 Milo的海域閱讀(285) | 評論 (0) | 編輯收藏

A text2graph tool: Graphviz

Graphviz: a Text to Graph tool

Download:
http://www.graphviz.org/Download..php

Install:
http://www.graphviz.org/Download_linux_rhel.php

Document:
http://www.graphviz.org/Documentation.php

Example:

$ cat cluster.dot
digraph G {

        subgraph cluster_0 {
                style=filled;
                color=lightgrey;
                node [style=filled,color=white];
                a0 -> a1 -> a2 -> a3;
                label = "process #1";
        }

        subgraph cluster_1 {
                node [style=filled];
                b0 -> b1 -> b2 -> b3;
                label = "process #2";
                color=blue
        }
        start -> a0;
        start -> b0;
        a1 -> b3;
        b2 -> a3;
        a3 -> a0;
        a3 -> end;
        b3 -> end;

        start [shape=Mdiamond];
        end [shape=Msquare];
}

$ dot -Tpng cluster.dot -o cluster.png
$ gnome-open cluster.png

More examples:
http://www.graphviz.org/Gallery.php

posted @ 2012-05-07 14:47 Milo的海域閱讀(549) | 評論 (0) | 編輯收藏

Use iozone to test file system performance

iozone 是一個開源的文件系統benchmark 測試工具。可用來檢測當前或者指定磁盤的讀寫性能。

http://www.iozone.org/

安裝

先確保rpmforge repository源已經安裝。具體參考：
http://www.tkk7.com/miaoyachun/archive/2012/02/03/369319.html

然后直接yum安裝

yum install iozone

測試

iozone  -i 0 -r 32 -s 2097152
        Iozone: Performance Test of File I/O
                Version $Revision: 3.394 $
                Compiled for 64 bit mode.
                Build: linux

        Contributors:William Norcott, Don Capps, Isom Crawford, Kirby Collins
                     Al Slater, Scott Rhine, Mike Wisner, Ken Goss
                     Steve Landherr, Brad Smith, Mark Kelly, Dr. Alain CYR,
                     Randy Dunlap, Mark Montague, Dan Million, Gavin Brebner,
                     Jean-Marc Zucconi, Jeff Blomberg, Benny Halevy, Dave Boone,
                     Erik Habbinga, Kris Strecker, Walter Wong, Joshua Root,
                     Fabrice Bacchella, Zhenghua Xue, Qin Li, Darren Sawyer.
                     Ben England.

        Run began: Wed Apr 25 19:36:55 2012

        Record Size 32 KB
        File size set to 2097152 KB
        Command line used: iozone -i 0 -r 32 -s 2097152
        Output is in Kbytes/sec
        Time Resolution = 0.000001 seconds.
        Processor cache size set to 1024 Kbytes.
        Processor cache line size set to 32 bytes.
        File stride size set to 17 * record size.
                                                            random  random    bkwd   record   stride
              KB  reclen   write rewrite    read    reread    read   write    read  rewrite     read   fwrite frewrite   fread  freread
         2097152      32  844758 2001670

iozone test complete.

posted @ 2012-04-26 10:49 Milo的海域閱讀(493) | 評論 (0) | 編輯收藏

Maven + PHP + Jetty

http://www.owengriffin.com/posts/2010/04/22/Writing_PHP_applications_with_Maven_and_Jetty.html
實驗了下，是可以的。不過用的maven3

posted @ 2012-04-11 14:32 Milo的海域閱讀(347) | 評論 (0) | 編輯收藏

innobackupex & FLUSH TABLES WITH READ LOCK

當innobackupex 做全備的時候(my version 1.6.5), 當備份到MyISAM數據時, innobackupex 會flush tables with read lock, 來禁止MyISAM的寫操作. (假設沒有--no-lock選項)

sub backup {

    if (!$option_incremental && !$option_no_lock) {
        # make a prep copy before locking tables, if using rsync
        backup_files(1);

        # flush tables with read lock
        mysql_lockall();
    }

    if ($option_slave_info) {
        write_slave_info();
    }

}

sub mysql_lockall {

    if (compare_versions($mysql_server_version, '4.0.22') == 0
        || compare_versions($mysql_server_version, '4.1.7') == 0) {
        # MySQL server version is 4.0.22 or 4.1.7
        mysql_send "COMMIT;";
        mysql_send "FLUSH TABLES WITH READ LOCK;";
    } else {
        # MySQL server version is other than 4.0.22 or 4.1.7
        mysql_send "FLUSH TABLES WITH READ LOCK;";
        mysql_send "COMMIT;";
    }
    write_binlog_info;

}

但是如果備份的時候還有很重的workload, "flush tables with read lock" 可能會比較耗時. 這里參考了：

http://www.mysqlperformanceblog.com/2010/04/24/how-fast-is-flush-tables-with-read-lock/

看了下--no-lock的選項說明：

    --no-lock
        Use this option to disable table lock with "FLUSH TABLES WITH READ
        LOCK". Use it only if ALL your tables are InnoDB and you DO NOT CARE
        about the binary log position of the backup.

如果我們能保證workload僅僅是innodb相關的，我們可以使用這個選項。

記得在1.5版本的時候，使用--no-lock選項會導致xtrabackup_slave_info沒有保存備份時的logfile & pos. 這個問題在1.6.5被解決了

    if ($option_slave_info) {
        write_slave_info();
    }

xtrabackup_slave_info & xtrabackup_binlog_info文件在1.5版本是在mysql_lockall函數里更新的。但是新版本已經把write_slave_info提到mysql_lockall外面了。

posted @ 2012-04-10 17:19 Milo的海域閱讀(676) | 評論 (0) | 編輯收藏

Use PHP var_export API to dump data to file

Some time we may not want export complex hash to console but file, we can do like this to dump to file by var_export

<?php

$a = array('abc'=>"123");

# var dump
var_dump($a);

# var_export
echo var_export($a);

# export to file
$b = var_export($a, true);
error_log($b."\n", 3, "/tmp/ymiao.log");

Result:

cat /tmp/ymiao.log

array (
'abc' => '123',
)

posted @ 2012-04-10 10:54 Milo的海域閱讀(385) | 評論 (0) | 編輯收藏

innobackupex 1.6.4 need empty datadir when copy-back

When restore by xtrabackup '--copy-back' with version 1.6.4, you may get error:

IMPORTANT: Please check that the copy-back run completes successfully.
At the end of a successful copy-back run innobackupex-1.6.4
prints "completed OK!".

Original data directory is not empty! at innobackupex-1.6.4 line 544.

when read those lines we found that:

    # check that original data directories exist and they are empty
    if_directory_exists_and_empty($orig_datadir, "Original data");
    if_directory_exists_and_empty($orig_ibdata_dir, "Original InnoDB data");
    if_directory_exists_and_empty($orig_iblog_dir, "Original InnoDB log");

Google for reason for this check and find it mentioned in:

http://www.mysqlperformanceblog.com/2011/12/19/percona-xtrabackup-1-6-4/

innobackupex did not check that MySQL datadir was empty before –copy-back was run. With this bug fix,
innobackupex will now error out of the –copy-back operation if the destination is not empty, avoiding
potential data loss or a strang combination of a restored backup and previous data. Bug Fixed: #737569 (Valentine Gostev)

posted @ 2012-04-03 13:01 Milo的海域閱讀(699) | 評論 (0) | 編輯收藏

Setup MySQL CDT DEV Enviroment

1. install bzr tool, ref http://dev.mysql.com/doc/refman/5.1/en/installing-development-tree.html
2. download mysql 5.1 code from trunk
3. autoreconf --force --install
4. ./configure --with-debug --without-libedit --with-plugins=innobase
5. make & sudo make install
6. setup eclipse cdt env
   a. startup eclipse by sudo cmd or root user
   b. build project
   c. set debug diag, ref http://forge.mysql.com/wiki/Eclipse/CDT_on_Linux_and_Mac_OS_X, here is my "program parameters" when startup mysqld instance:

--datadir=/var/lib/mysql --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --port=3306 --socket=/tmp/mysql.sock --default-storage-engine=innodb

posted @ 2012-03-23 17:49 Milo的海域閱讀(294) | 評論 (0) | 編輯收藏

miaoyachun

Use ssh-copy-id avoid inputing password

幾個ssh管道用法

Notes for SNMP

A text2graph tool: Graphviz

Use iozone to test file system performance

Maven + PHP + Jetty

innobackupex & FLUSH TABLES WITH READ LOCK

Use PHP var_export API to dump data to file

innobackupex 1.6.4 need empty datadir when copy-back

Setup MySQL CDT DEV Enviroment

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