Browsing the web I found this interesting presentation by John Allspaw:
Slides from ‘Capacity Planning for LAMP’ talk at MySQL Conf 2007.
(Damn, I had to clean out the embedded flash because of invalid markup…)
I’m preparing some stuff related to RRDTool, I’ll post soon here some code snippets.
Depending on the release of awk it could be:
#!/usr/bin/gawk -f { if ( ($NF) in stats ) { stats[$NF] = stats[$NF]+1; } else { stats[$NF]=1; } } END { for ( var in stats) { print var " = " stats[var]; } }
I saved the script as netstat_c.
I have to filter my netstat output to match only my tcp sockets prior to pipe the output to the script.
On linux:
$ netstat -a | grep ^tcp | netstat_c LISTEN = 13 ESTABLISHED = 74 TIME_WAIT = 7
This is great to check my webserver connections when I do stress tests.
You have your brand new RAC deployed on a cluster and you want to manage your backups through a recovery catalog.
Suppose you don’t have a dedicate server to host your catalog, perhaps you wouldn’t configure your catalog as a RAC database: so why don’t you use Clusterware to configure your catalog as a single instance in cold failover?
OTN has a very nice whitepaper describing how to protect a single instance database. This can be nicely applied on 10g, 10gR2 or 11g: Using Oracle Clusterware to Protect A Single Instance Oracle Database 11g.
Clusterware is appealing also for traditional cold failover clusters. Licensing allows you to use Clusterware as far as you protect Oracle software or 3rd party software that use Oracle as database backend.
Oracle Dataguard has his own command-line dgmgrl to check the whole dataguard configuration status.
At least you should check that the show configuration command returns SUCCESS.
This is an hypothetic script:
#!/bin/bash export ORACLE_HOME=/u1/app/oracle/product/10.2.0 export ORACLE_SID=orcldg result=`echo "show configuration;" | \ $ORACLE_HOME/bin/dgmgrl sys/strongpasswd | \ grep -A 1 "Current status for" | grep -v "Current status for"` if [ "$result" = "SUCCESS" ] ; then exit 0 else exit 1 fi
Another script should check for the gap between production online log and the log stream received by the standby database. This can be accomplished with v$managed_standby view.
The Total Block Gap between production and standby can be calculated this way:
Sum all blocks from v$archived_logs where seq# between Current Standby Seq# and Current Production Seq#. Then add current block# of the production LGWR process and subtract current block# from RFS standby process. This gives you total blocks even if there is a log sequence gap between sites.
This is NOT the gap of online log APPLIED to the standby database. THIS IS THE GAP OF ONLINE LOG TRANSMITTED TO THE STANDBY RFS PROCESS and can be used to monitor your dataguard transmission from production to disaster recovery environment.
This is an excerpt of such script (please take care that it does not check against RFS failures, so it can fails when RFS is not alive):
#!/u1/app/oracle/product/10.2.0/perl/bin/perl -w use DBI; use DBD::Oracle qw(:ora_session_modes); # DB connection # my $prod = "orclprod"; my $stby = "orcldr"; my $prodh; unless ($prodh = DBI->connect('dbi:Oracle:'.$prod, 'sys', 'strongpassword', {PrintError=>0, AutoCommit => 0, ora_session_mode => ORA_SYSDBA})) { print "Error connecting to DB: $DBI::errstr\n"; exit(1); } $prodh->{RaiseError}=1; my $stbyh; unless ($stbyh = DBI->connect('dbi:Oracle:'.$stby, 'sys', 'strongpassword', {PrintError=>0, AutoCommit => 0, ora_session_mode => ORA_SYSDBA})) { print "Error connecting to DB: $DBI::errstr\n"; $prodh->disconnect; exit(1); } $stbyh->{RaiseError}=1; my $sth; ### query prod $sth = $prodh->prepare( < <EOSQL ); select SEQUENCE#, BLOCK# from v\$managed_standby where process='LGWR' EOSQL $sth->execute(); my ($psequence, $pblock) = $sth->fetchrow_array(); $sth->finish(); ### query stdby $sth = $stbyh->prepare( < <EOSQL ); select SEQUENCE#, BLOCK# from v\$managed_standby where process='RFS' and client_process='LGWR' EOSQL $sth->execute(); my ($ssequence, $sblock) = $sth->fetchrow_array(); $sth->finish(); printf ("PROD : %10d %10d\n", $psequence, $pblock); printf ("STANDBY: %10d %10d\n", $ssequence, $sblock); $sth = $stbyh->prepare( < <EOSQL ); select nvl(sum(blocks),0) + $pblock - $sblock as BLOCK_GAP from v\$archived_log where sequence# between $ssequence and $psequence EOSQL $sth->execute(); my ($blockgap) = $sth->fetchrow_array(); $sth->finish(); printf ("%-10d blocks gap\n", $blockgap); $stbyh->disconnect; $prodh->disconnect;
Any comment is appreciated!