resolved - Artifactory: Return code is: 502, ReasonPhrase:cannot connect

Today when I tried to visit Maven Artifactory, below error prompted in browser:

Return code is: 502, ReasonPhrase:cannot connect.

And here's the log in

2016-08-19 22:48:19,942 [art-init] [ERROR] (o.a.w.s.ArtifactoryContextConfigListener:91) - Application could not be initialized: Connection refused
java.lang.reflect.InvocationTargetException: null
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.7.0_51]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) ~[na:1.7.0_51
]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:
1.7.0_51]

......

Firstly, I thought it was caused by JDBC issue, here's the config in JDBC config file storage.properties:

# cat /u01/oracle/artifactory_home/etc/storage.properties
type=oracle
driver=oracle.jdbc.OracleDriver
url=jdbc:oracle:thin:@localhost:1521:ORCL
username=artifactory
password=password1

I tried connect to DB using sqlplus to have a test, it's OK:

[root@testvm ~]# su - oracle
[oracle@testvm ~]$ export ORACLE_HOME=/u01/oracle/db12c/product/12.1.0/dbhome_1
[oracle@testvm ~]$ ORACLE_SID=orcl
[oracle@testvm ~]$ export PATH=$ORACLE_HOME/bin:$PATH
[oracle@testvm ~]$ sqlplus artifactory/password1

SQL*Plus: Release 12.1.0.1.0 Production on Mon Aug 22 03:28:20 2016

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Last Successful login time: Mon Aug 22 2016 03:21:26 +00:00

Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL>

After some debugging, I found the issue was caused by proxy setting. We should disable it like below:

[oracle@testvm ~]# grep proxy /etc/profile
#export http_proxy=http://myproxy.example.com:80/

Then log out and log on the host again, and ran below commands to shutdown/startup Artifactory:

[oracle@testvm ~]$ export ORACLE_HOME=/u01/oracle/db12c/product/12.1.0/dbhome_1/
[oracle@testvm ~]$ export ORACLE_SID=orcl
[oracle@testvm ~]$ export PATH=$PATH:$ORACLE_HOME/bin
[oracle@testvm ~]$ /u01/oracle/apache-tomcat-7.0.52/bin/shutdown.sh
[oracle@testvm ~]$ /u01/oracle/apache-tomcat-7.0.52/bin/startup.sh

After this, Artifactory started working again.

remove entries in perl array with specified value

Assume that in array @array_filtered:

my @array_filtered = ("your", "array", "here", 1, 3, 8, "here", 2, 5, 9, "sit", "here",3, 4, 7,"yes","now",8,1,7,6); #or my @array_filtered=qw(your array here 1 3 8 here 2 5 9 sit here 3 4 7 yes now 8 1 7 6) which uses Alternative Quotes(q, qq, qw, qx)

You want to remove entries that have value "here" or "now" and it's following 3 entries, you can use splice:

#!/usr/bin/perl
my @array_filtered = ("your", "array", "here", 1, 3, 8, "here", 2, 5, 9, "sit", "here",3, 4, 7,"yes","now",8,1,7,6);
my @search_for = ("here","now");
#return keys that have specified value, =~/!~ for regular expression, eq/ne for string, ==/!= for number. or use unless()/if(not()). use m{} instead of // if there's too much / in the expression and you're tired of using \/ to escape them.

$search_for_s=join('|',@search_for);
@index_all = grep { $array_filtered[$_] =~ /$search_for_s/ } 0..$#array_filtered;

for($i=0;$i<=$#index_all;$i++) {
@index_all_one = grep { $array_filtered[$_] =~ /$search_for_s/ } 0..$#array_filtered;
splice(@array_filtered,$index_all_one[0],4);
#print $indexone."\n"
}

print "@array_filtered"."\n";

The output is "your array sit yes 6".

PS:

  • For more info about perl regular expression(such as operators<m, s, tr> and their modifiers, complex regular expression cheat sheet<.\s\S\d\D\w\W[aeiou][^aeiou](foo|bar), \G, $, $&, $`, $'> and more), you can refer to this article.
  • The following is about perl alternative quotes:

q// is generally the same thing as using single quotes - meaning it doesn't interpolate values inside the delimiters.
qq// is the same as double quoting a string. It interpolates.
qw// return a list of white space delimited words. @q = qw/this is a test/ is functionally the same as @q = ('this', 'is', 'a', 'test')
qx// is the same thing as using the backtick operators.

Resolved - AttributeError: 'NoneType' object has no attribute '_imgName'

Today when I tried to list Virtual Machines on one Oracle OVMM, error message prompted:

[root@ovmm_test ~]# ovm -uadmin -ppassword vm ls
Traceback (most recent call last):
  File "/usr/bin/ovm", line 43, in ?
    ovmcli.ovmmain.main(sys.argv[1:])
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmmain.py", line 122, in main
    return ovm.ovmcli.runcmd(args)
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmcli.py", line 147, in runcmd
    return method(options)
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmcli.py", line 1578, in do_vm_ls
    result.append((serverpool._serverPoolName, vm._imgName))
AttributeError: 'NoneType' object has no attribute '_imgName'

Then I tried list VMs by server pool:

[root@ovmm_test ~]# ovm -uadmin -ppassword vm ls -s Pool1_test
Name                 Size(MB) Mem   VCPUs Status  Server_Pool
testvm1              17750    8196  4     Running Pool1_test
testvm2               50518    8196  4     Running Pool1_test
testvm3          19546    8192  2     Running Pool1_test
testvm4          50518    20929 4     Running Pool1_test
testvm5          19546    8192  2     Running Pool1_test
[root@ovmm_test ~]# ovm -uadmin -ppassword vm ls -s Pool1_test_A
Traceback (most recent call last):
  File "/usr/bin/ovm", line 43, in ?
    ovmcli.ovmmain.main(sys.argv[1:])
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmmain.py", line 122, in main
    return ovm.ovmcli.runcmd(args)
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmcli.py", line 147, in runcmd
    return method(options)
  File "/usr/lib/python2.4/site-packages/ovmcli/ovmcli.py", line 1578, in do_vm_ls
    result.append((serverpool._serverPoolName, vm._imgName))
AttributeError: 'NoneType' object has no attribute '_imgName'

One pool was working and the other was not, so the problematic VMs must reside in pool Pool1_test_A.

Another symptom was that, although ovmcli wouldn't work, the OVMM GUI worked as expected and returns all the VMs.

As ovmcli read entries from Oracle DB(SID XE) on OVMM, so the issue maybe caused by the inconsistency between DB & OVMM agent DB.

I got the list of all VMs on the problematic server pool from OVMM GUI, and then ran the following query to get all entries in DB:

select IMG_NAME from OVS_VM_IMG where SITE_ID=110 and STATUS !='Running' and length(IMG_NAME)>50; #Pool1_test_A was with ID 110, got from table OVS_SITE. I used length() here because in the problematic server pool, VMs all should have IMG_NAME with more than 50 characters; if less than 50, then they were VM templates which should have no issue

Comparing the output from OVMM GUI & OVM DB, I found some entries which only existed in DB. And for all of these entries, they all had "Status" in "Creating", and also the

select IMG_NAME from OVS_VM_IMG where STATUS='Creating';

Then I removed these weird entries:

delete from OVS_VM_IMG where SITE_ID=110 and STATUS !='Running' and length(IMG_NAME)>50; #you can try rename/drop table OVS_VM_IMG(alter table TBL1 rename to TBL2; drop table TBL1), remove entries in backup table(OVS_VM_IMG_bak20141106), and then rename backup table(OVS_VM_IMG_bak20141106) to OVS_VM_IMG if failed at this step caused by foreign key or other reasons (don't do this, it will cause problem about constraints etc)

After this, the issue got resolved.

PS:

  1. After you removed entries with STATUS being "Creating", and if you found some more entries of this kind occurred in OVM DB, then maybe it's caused by VM templates not working or DB table corrupted. In this case, you'll need recover OVMM by rollong back to previous version of your backup, and then import VM templates/VM images etc.
  2. Actually the issue was caused by breaking constraint(constraint name conflicts caused by table backups. So better not to backup table when doing operation against OVMM DB using sql directly). This issue can be resolved by alter constraint name, and later remove backup tables.

perl tips

##system value
$count=`wc -l space_mail_info.txt | sed 's/ space_mail_info.txt//'`;
if ($count >= 1) {
system('cat space_mail_info.txt | /bin/mailx -s "SAs - Space Warning - please work with component owners to free space" test@example.com');
}
##arrays
#!/usr/bin/perl -w
my @animals = ("dog", "pig", "cat");
print "The last element of array \$animals is : ".$animals[$#animals]."\n";
print "@animals"."\n"; #will print values of array, delimitered by space
print $#animals."\n"; #the last key number of array, $#animals+1 is the number of array
if(@animals>2){
print "more than 2 animals found\n";
}
else{
print "less than 2 animals found\n"
}
foreach(@animals){
print $_."\n";
}
##hashes
my %fruit_color=("apple", "red", "banana", "yellow");
print "Color of banana is : ".$fruit_color{"banana"}."\n";

for $char (keys %fruit_color)
{
print("$char => $fruit_color{$char}\n");
}

##references
my $variables = {
scalar  =>  {
description => "single item",
sigil => '$',
},
array   =>  {
description => "ordered list of items",
sigil => '@',
},
hash    =>  {
description => "key/value pairs",
sigil => '%',
},
};
print "Scalars begin with a $variables->{'scalar'}->{'sigil'}\n";

##Files and I/O
open (my $passwd, "<", "/etc/passwd2") or die ("can  a not open");
while (<$passwd>) {
print $_ if $_ =~ "test";
}
close $passwd or die "$passwd: $!";
my $next = "doing a first";
$next =~ s/first/second/;
print $next."\n";

my $email = "testaccount\@doxer.org";
if ($email =~ /([^@]+)@(.+)/) {
print "Username is : $1\n";
print "Hostname is : $2\n";
}

##Subroutines
sub multiply{
my ($num1, $num2) = @_;
my $result = $num1 * $num2;
return $result;
}

my $result2 = multiply(3, 5);
print "3 * 5 = $result2\n";

##or
! system('date') or die("failed it"); #if a subroutine returns ok, it'll return 0
PS:

resolved - sudo: sorry, you must have a tty to run sudo

The error message below sometimes will occur when you run a sudo <command>:

sudo: sorry, you must have a tty to run sudo

To resolve this, you may comment out "Defaults requiretty" in /etc/sudoers(revoked by running visudo). Here is more info about this method.

However, sometimes it's not convenient or even not possible to modify /etc/sudoers, then you can consider the following:

echo -e "<password>\n"|sudo -S <sudo command>

For -S parameter of sudo, you may refer to sudo man page:

-S' The -S (stdin) option causes sudo to read the password from the standard input instead of the terminal device. The password must be followed by a newline character.

So here -S bypass tty(terminal device) to read the password from the standard input. And by this, we can now pipe password to sudo.

PS:

From comments, you may also try below:

1. Comment out Defaults requiretty in /etc/sudoers

2. Defaults:[username] !requiretty #change [username]

3. You can use ssh -t to force pseudo-tty allocation. e.g. ssh -t user1@hostname1 "sudo df -h"

4. If you met error "PTY allocation request failed on channel 0" when SSH, then you can increase pty number

sysctl -a|grep -i pty

kernel.pty.max = 4096
kernel.pty.nr = 237

vi /etc/sysctl.conf #kernel.pty.max = 10000

sysctl -p;sysctl -a|grep pty

Resolved - print() on closed filehandle $fh at ./perl.pl line 6.

You may find that print sometimes won't work as expected in perl, for example:

[root@centos-doxer test]# cat perl.pl
#!/usr/bin/perl
use warnings;
open($fh,"test.txt");
select $fh;
close $fh;
print "test";

You may expect "test" to be printed, but actually you got error message:

print() on closed filehandle $fh at ./perl.pl line 6.

So how's this happened? Please see my explanation:

[root@centos-doxer test]# cat perl.pl
#!/usr/bin/perl
use warnings;
open($fh,"test.txt");
select $fh;
close $fh; #here you closed $fh filehandle, but you should now reset filehandle to STDOUT
print "test";

Now here's the updated script:

#!/usr/bin/perl
use warnings;
open($fh,"test.txt");
select $fh;
close $fh;
select STDOUT;
print "test";

This way, you'll get "test" as expected!

 

Oracle BI Publisher reports - send mail when filesystems getting full

Let's assume you have one Oracle BI Publisher report for filesystem checking. And now you want to write script for checking that report page and send mail to system admins when filesystems are getting full. As the default output of Oracle BI Publisher report needs javascript to work, and as you may know javascript is evil that wget/curl can not get them, so after log on, the next step you need to do is to find the html version's url of that report for you to use in your script(and the html page has all records when javascript one has only part of them):

BI_report_login

BI_export_html

 

Let's assume that the html's url is "http://www.example.com:9703/report.html", and the display of it was like the following:

bi report

Then here goes the script that will check this page for hosts that has less than 10% available space and send mail to system admins:

#!/usr/bin/perl
use HTML::Strip;
#hosts that do not need reporting
my @remove_list = qw(host1.example.com host2.example.com);
system("rm -f spacereport.html");
system("wget -q --no-proxy --no-check-certificate --post-data 'id=admin&passwd=password' 'http://www.example.com:9703/report.html' -O spacereport.html");
open($fh,"spacereport.html");

#or just @spacereport=<$fh>;
foreach(<$fh>){
push(@spacereport,$_);
}

#change array to hash
$index=0;
map {$pos{$index++}=$_} @spacereport;

#get location of <table> and </table>
#sort numerically ascending
for $char (sort {$a<=>$b} (keys %pos))
{
if($pos{$char} =~ /<table class="c27">/)
{
$table_start=$char;
}

if($pos{$char} =~ /<\/table>/)
{
$table_end=$char;
}

}

#get contents between <table> and </table>
for($i=$table_start;$i<=$table_end;$i++){
push(@table_array,$spacereport[$i]);
}

$table_htmlstr=join("",@table_array);

#get clear text between <table> and </table>
my $hs=HTML::Strip->new();
my $clean_text = $hs->parse($table_htmlstr);
$hs->eof;

@array_filtered=split("\n",$clean_text);

#remove empty array element
@array_filtered=grep { !/^\s+$/ } @array_filtered;

#remove entries from showing
$remove_list_s=join('|',@remove_list);
@index_all = grep { $array_filtered[$_] =~ /$remove_list_s/ } 0..$#array_filtered;

for($i=0;$i<=$#index_all;$i++) {
@index_all_one = grep { $array_filtered[$_] =~ /$remove_list_s/ } 0..$#array_filtered;
splice(@array_filtered,$index_all_one[0],4);
}

system("rm -f space_mail_warning.txt");
open($fh_mail_warning,">","space_mail_warning.txt");
select $fh_mail_warning;
for($j=4;$j<=$#array_filtered;$j=$j+4){
#put lines that has free space lower than 10% to space_mail_warning.txt
if($array_filtered[$j+2] <= 10){
print "Host: ".$array_filtered[$j]."\n";
print "Part: ".$array_filtered[$j+1]."\n";
print "Free(%): ".$array_filtered[$j+2]."\n";
print "Free(GB): ".$array_filtered[$j+3]."\n";
print "============\n\n";
}
}
close $fh_mail_warning;

system("rm -f space_mail_info.txt");
open($fh_mail_info,">","space_mail_info.txt");
select $fh_mail_info;
for($j=4;$j<=$#array_filtered;$j=$j+4){
#put lines that has free space lower than 15% to space_mail_info.txt
if($array_filtered[$j+2] <= 15){
print "Host: ".$array_filtered[$j]."\n";
print "Part: ".$array_filtered[$j+1]."\n";
print "Free(%): ".$array_filtered[$j+2]."\n";
print "Free(GB): ".$array_filtered[$j+3]."\n";
print "============\n\n";
}
}
close $fh_mail_info;

#send mail
#select STDOUT;
if(-s "space_mail_warning.txt"){
system('cat space_mail_warning.txt | /bin/mailx -s "Space Warning - please work with component owners to free space" sysadmins@example.com');
} elsif(-s "space_mail_info.txt"){
system('cat space_mail_info.txt | /bin/mailx -s "Space Info - Space checking mail" sysadmins@example.com');
}

wget and curl tips

Imagine you want to download all files under http://www.example.com/2013/downloads, and not files under http://www.example.com/2013 except for directory 'downloads', then you can do this:

wget -r --level 100 -nd --no-proxy --no-parent --reject "index.htm*" --reject "*gif" 'http://www.example.com/2013/downloads/' #--level 100 is large enough, as I've seen no site has more than 100 levels of sub-directories so far.

wget -p -k --no-proxy --no-check-certificate --post-data 'id=username&passwd=password' <url> -O output.html

wget --no-proxy --no-check-certificate --save-cookies cookies.txt <url>

wget --no-proxy --no-check-certificate --load-cookies cookies.txt <url>

curl -k -u 'username:password' <url>

curl -k -L -d id=username -d passwd=password <url>

curl --data "loginform:id=username&loginform:passwd=password" -k -L <url>

curl -i -u username:password -H X-Oracle-UserId:myname@example.com -H X-Oracle-IdentityDomain:domainname -X GET "https://login.example.com:443/api/v1/users?userLogin"

Here's one curl example to get SSL certs info on LTM:

#!/bin/bash
path="/var/tmp"
path_root="/var/tmp"

agent="Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.2)"

curl -v -L -k -A "$agent" -c ${path}/cookie "https://ltm-url/tmui/login.jsp?msgcode=1&"

curl -v -L -k -A "$agent" -b ${path}/cookie -c ${path}/cookie -e "https://ltm-url/tmui/login.jsp?msgcode=1&" -d "username=myusername&passwd=mypassword" "https://ltm-url/tmui/logmein.html?msgcode=1&"

curl -v -L -k -A "$agent" -b ${path}/cookie -c ${path}/cookie -o ${path_root}/certs-env.html "https://ltm-url/tmui/Control/jspmap/tmui/locallb/ssl_certificate/list.jsp?&startListIndex=0&showAll=true"

Now you can have a check of /var/tmp/certs-env.html for SSL certs info of Big IP VIPs.

PS:

To use private CA/public cert/private key, you should use below in curl:

curl -v --cacert your-root-ca.crt --cert your-public-cert.crt --key your-private.key --pass mypass -u "username:password" https://url
In this command, your-public-cert.crt is the public cert that you have trusted,your-private.key is the private RSA key portion of the cert that is used to sign the request, and “username:password” should be replaced with the correct username and password.

Also, if you’re using an intermediate cert, you can provide it in one command like so:

curl -v --cacert your-root-ca.crt --cert <(cat your-public-cert.crt  intermediate.crt ) --key your-private.key --pass mypass -u “username:password" https://url

Oracle VM operations - poweron, poweroff, status, stat -r

Here's the script:
#!/usr/bin/perl
#1.OVM must be running before operations
#2.run ovm_vm_operation.pl status before running ovm_vm_operation.pl poweroff or poweron
use Net::SSH::Perl;
$host = $ARGV[0];
$operation = $ARGV[1];
$user = 'root';
$password = 'password';

$newname=$ARGV[2];
$newcpu=$ARGV[3];
$newmemory=$ARGV[4];
$newpool=$ARGV[5];
$newtmpl=$ARGV[6];
$newbridge=$ARGV[7];
$newbridge2=$ARGV[8];
$newvif='vif0';
$newvif2='VIF1';

if($host eq "help") {
print "$0 OVM-name status|poweron|poweroff|reboot|stat-r|stat-r-all|pool|new vmname 1 4096 poolname tmplname FE BE\n";
exit;
}

$ssh = Net::SSH::Perl->new($host);
$ssh->login($user,$password);

if($operation eq "status") {
($stdout,$stderr,$exit) = $ssh->cmd("ovm -uadmin -ppassword vm ls|grep -v VM_test");
open($host_fd,'>',"/var/tmp/${host}.status");
select $host_fd;
print $stdout;
close $host_fd;
} elsif($operation eq "poweroff") {
open($poweroff_fd,'<',"/var/tmp/${host}.status");
foreach(<$poweroff_fd>){
if($_ =~ "Server_Pool|OVM|Powered") {
next;
}
if($_ =~ /(.*?)\s+([0-9]{1,})\s+([0-9]{1,})\s+([0-9]{1,})\s+([a-zA-Z]{1,})\s+(.*)/){
$ssh->cmd("ovm -uadmin -ppassword vm poweroff -n $1 -s $6 -f");
sleep 12;
}
}
} elsif($operation eq "reboot") {
open($poweroff_fd,'<',"/var/tmp/${host}.status");
foreach(<$poweroff_fd>){
if($_ =~ "Server_Pool|OVM|Powered") {
next;
}
if($_ =~ /(.*?)\s+([0-9]{1,})\s+([0-9]{1,})\s+([0-9]{1,})\s+([a-zA-Z]{1,})\s+(.*)/){
$ssh->cmd("ovm -uadmin -ppassword vm reboot -n $1 -s $6");
sleep 12;
}
}
} elsif($operation eq "poweron") {
open($poweron_fd,'<',"/var/tmp/${host}.status");
foreach(<$poweron_fd>){
if($_ =~ "Server_Pool|OVM|Running|used|poweroff") {
next;
}
if($_ =~ /(.*?)\s+([0-9]{1,})\s+([0-9]{1,})\s+([0-9]{1,})\s+([a-zA-Z]{1,})\s+Off(.*)/){
$ssh->cmd("ovm -uadmin -ppassword vm poweron -n $1 -s $6");
#print "ovm -uadmin -ppassword vm poweron -n $1 -s $6";
sleep 15;
}
}
} elsif($operation eq "stat-r") {
open($poweroff_fd,'<',"/var/tmp/${host}.status");
foreach(<$poweroff_fd>){
if($_ =~ /(.*?)\s+([0-9]{1,})\s+([0-9]{1,})\s+([0-9]{1,})\s+(Shutting\sDown|Initializing|Error|Unknown|Rebooting|Deleting)\s+(.*)/){
#print "ovm -uadmin -ppassword vm stat -r -n $1 -s $6";
$ssh->cmd("ovm -uadmin -ppassword vm stat -r -n $1 -s $6");
sleep 1;
}
}
} elsif($operation eq "stat-r-all") {
open($poweroff_fd,'<',"/var/tmp/${host}.status");
foreach(<$poweroff_fd>){
$ssh->cmd("ovm -uadmin -ppassword vm stat -r -n $1 -s $6");
sleep 1;
}
} elsif($operation eq "pool") {
($stdoutp,$stderrp,$exitp) = $ssh->cmd("ovm -uadmin -ppassword svrp ls|grep Inactive");
open($host_fdp,'>',"/var/tmp/${host}-poolstatus");
select $host_fdp;
print $stdoutp;
close $host_fdp;
} elsif($operation eq "new") {
($stdoutp,$stderrp,$exitp) = $ssh->cmd("ovm -uadmin -ppassword tmpl ls -s $newpool | grep $newtmpl");
if($stdoutp =~ /$newtmpl/){
($stdoutp2,$stderrp2,$exitp2) = $ssh->cmd("ovm -uadmin -ppassword vm new -m template -s $newpool -t $newtmpl -n $newname -c password");
if($stdoutp2 =~ /is being created/){
print "Creating VM $newname in pool $newpool on OVMM $host now!"."\n";
while(1){
($stdoutp3,$stderrp3,$exitp3) = $ssh->cmd("ovm -uadmin -ppassword vm stat -n $newname -s $newpool");
if($stdoutp3 =~ /Powered Off/){
print "Done VM creation."."\n";
last;
}
sleep 300
}

print "Setting Cpu/Memory now."."\n";
($stdoutp32,$stderrp32,$exitp32) = $ssh->cmd("ovm -uadmin -ppassword vm conf -n $newname -s $newpool -x $newmemory -m $newmemory -c $newcpu -P");
sleep 2;

print "Creating NICs now."."\n";
($stdoutp4,$stderrp4,$exitp4) = $ssh->cmd("ovm -uadmin -ppassword vm nic conf -n $newname -s $newpool -N $newvif -i VIF0 -b $newbridge");
sleep 2;
($stdoutp5,$stderrp5,$exitp5) = $ssh->cmd("ovm -uadmin -ppassword vm nic add -n $newname -s $newpool -N $newvif2 -b $newbridge2");
sleep 2;

print "Powering on VM now."."\n";
($stdoutp6,$stderrp6,$exitp6) = $ssh->cmd("ovm -uadmin -ppassword vm poweron -n $newname -s $newpool");
sleep 30;

while(1){
($stdoutp7,$stderrp7,$exitp7) = $ssh->cmd("ovm -uadmin -ppassword vm info -n $newname -s $newpool");
if($stdoutp7 =~ /Running on: sl/){
print "VM is now Running, you can configure VM on hypervisor now:"."\n";
print $stdoutp7."\n";
last;
}
sleep 30;
}

#($stdoutp8,$stderrp8,$exitp8) = $ssh->cmd("ovm -uadmin -ppassword vm ls -l | grep $newname");
#print "You can configure VM on hypervisor now:"."\n";
#print $stdoutp8."\n";
} else {
print $stdoutp2."\n";
exit;
}
} else {
print "No template named $newtmpl in pool $newpool\n";
exit;
}
}

You can use the following to make the script run in parallel:

for i in <all OVMs>;do (./ovm_vm_operation.pl $i status &);done

avoid putty ssh connection sever or disconnect

After sometime, ssh will disconnect itself. If you want to avoid this, you can try run the following command:

while [ 1 ];do echo hi;sleep 60;done &

This will print message "hi" every 60 seconds on the standard output.

PS:

You can also set some parameters in /etc/ssh/sshd_config, you can refer to http://www.doxer.org/make-ssh-on-linux-not-to-disconnect-after-some-certain-time/