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This chapter discusses the following topics:
Note: A migration requirement is that both the master and backup machines must be running the same release of the BEA TUXEDO software.
Whether you need to migrate all or portions of an application, the changes to the application setup must be made with minimal service disruption. Machines, networks, databases, the BEA TUXEDO system, and the application all need to be maintained. The BEA TUXEDO system provides a way to migrate the applications so that they can be serviced.
The BEA TUXEDO system offers migration tools that can also be used to recover from a machine crash, network partitions, database corruptions, BEA TUXEDO system problems, and application faults.
The following is a list of migration options:
By using a combination of these options and partitioned network recovery utilities, you can migrate entire machines.
Server migration is the process of moving one or more servers from one machine to another. One special instance of this process is the ability to switch master and backup machines. This type of switching is done by migrating the DBBL from the master machine to the backup machine. While this procedure is most frequently used when a network is partitioned, it is also useful in situations that require you to shut down the master machine.
Use the master
command to switch the master machine.
Command | Description |
---|---|
master(m) |
Switches the master machine to the backup machine or the reverse |
Use the tmadmin
(1)
master
(m
) command to switch master and
backup machines when the master machine must be shut down for maintenance, or when the
master machine is no longer accessible. Switching master and backup machines, however, is
only a first step. In most cases, application servers need to be migrated to alternate
sites, or the master machine needs to be restored. (These tasks are described in this
chapter.)
To switch the master and backup machines, call the tmadmin
(1) command interpreter with
the master
(m
) command from the
backup machine.
DBBL
process is migrated from the
master machine to the backup machine.
In the second example, because the master machine is not accessible from the backup
machine, the DBBL
process is created on the backup machine.
Listing 15-1 When the Master Machine Is Accessible from the Backup Machine
$ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. All rights reserved. > master are you sure? [y,n] y Migrating active DBBL from SITE1 to SITE2, please wait... DBBL has been migrated from SITE1 to SITE2 > q
Listing 15-2 When the Master Machine Is Not Accessible from the Backup Machine
$ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. All rights reserved. TMADMIN_CATT:199: Cannot become administrator. Limited set of commands available. > master are you sure? [y,n] y Creating new DBBL on SITE2, please wait... New DBBL created on SITE2 > q
Use the following two tmadmin
commands to migrate servers.
Use This Command | To |
---|---|
migrategroup(migg) |
Migrate servers in a group to their alternate location |
migratemach(migm) |
Migrate
servers by using LMID s |
The tmadmin
(1) migrategroup
(migg
) command takes the name of a
single server group as an argument. You must first shut down the servers to be migrated
with the -R
option (for
example, tmshutdown -R -g GROUP1
).
You must specify an alternate location in the LMID
parameter (for the server group being migrated) in the GROUPS
section of the UBBCONFIG
file. Servers in the group
must specify RESTART=Y
and the MIGRATE
option
must be specified in the RESOURCES
section of the UBBCONFIG
file.
If transactions are being logged for the server involved in a group migration, you may
need to move the TLOG
to
the backup machine, load it, and perform a warm start.
To migrate a server group when the alternate machine is accessible from the primary machine, complete the following steps.
tmshutdown
(1)
from the master machine with the -R
and -g
(group_name
) options. tmadmin
(1) from
the master machine. migrategroup
(migg
) command with group_name
as the argument. To migrate a server group when the alternate machine is not accessible from the primary machine, complete the following steps.
tmadmin
(1) from
the alternate machine. pclean
(pcl
) command with the primary
machine as the argument. migrategroup
(migg
) command with group_name
as the argument. tmboot
(1)
command to boot the server group. Listing 15-3 When the Alternate Machine Is Accessible from the Primary Machine
$ tmshutdown -R -g GROUP1 Shutting down server processes... Server ID = 1 Group ID = GROUP1 machine = SITE1: shutdown succeeded 1 process stopped. $ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. > migg GROUP1 migg successfully completed > q
Listing 15-4 When the Alternate Machine Is Not Accessible from the Primary Machine
$ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. > pclean SITE1 Cleaning the DBBL. Pausing 10 seconds waiting for system to stabilize. 3 SITE1 servers removed from bulletin board > migg GROUP1 migg successfully completed. > boot -g GROUP1 Booting server processes ... exec simpserv -A : on SITE2 -> process id=22699 ... Started. 1 process started. > q
Use the tmadmin
(1) migratemach
(migm
) command to migrate all server
groups from one machine to another when the primary machine must be shut down for
maintenance or when the primary machine is no longer accessible.
The command takes one logical machine identifier as an argument. The LMID
names the processor on which
the server group(s) have been running. The alternate location must be the same for all
server groups on the LMID
.
Servers on the LMID
must
specify RESTART=Y
and
the MIGRATE
options must
be specified in the RESOURCES
section of the UBBCONFIG
file. You must first shut down the server groups with the tmshutdown
(1) -R
option, and servers in the groups
must be marked as restartable.
To migrate a machine when the alternate machine is accessible from the primary machine, complete the following steps.
tmshutdown
(1)
from the master machine with the -R
and -l
(primary_machine
) options. tmadmin
(1)
from the master machine. migratemach
(migm
) command with primary_machine
as the
argument. To migrate a machine when the alternate machine is not accessible from the primary machine, complete the following steps.
tmadmin
(1)
from the alternate machine. pclean
(pcl
) command with primary_machine
as the
argument. migratemach
(migm
) command with primary_machine
as the
argument. boot
(b
) command to boot the server
groups. Listing 15-5 When the Alternate Machine Is Accessible from the Primary Machine
$ tmshutdown -R -l SITE1 Shutting down server processes... Server ID = 1 Group ID = GROUP1 machine = SITE1: shutdown succeeded 1 process stopped. $ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. > migm SITE1 migm successfully completed > q
Listing 15-6 When the Alternate Machine Is Not Accessible from the Primary Machine
$ tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. >pclean SITE1 Cleaning the DBBL. Pausing 10 seconds waiting for system to stabilize. 3 SITE1 servers removed from bulletin board > migm SITE1 migm successfully completed. > boot -l SITE1 Booting server processes ... exec simpserv -A : on SITE2 -- process id=22782 ... Started. 1 process started. >q
You can cancel a migration after a shutdown occurs, but before using the migrate
command, by using the -cancel
option with the migrate
command.
You can cancel a migration in the following ways:
tmadmin
(1)
migrategroup
(migg
) -cancel
command to cancel a server
migration. Server entries are deleted from the Bulletin Board. You must reboot the servers
once the migration procedure is canceled. tmadmin
(1)
migratemach
(migm
) -cancel
command to cancel a machine
migration. Listing 15-7 Canceling a Server Group Migration for Server Group GROUP1
$tmadmin tmadmin - Copyright © 1987-1990 AT&T; 1991-1993 USL. > psr -g GROUP1
a.out Name Queue Name Grp Name ID RqDone Ld Done Current Service ---------- ---------- -------- -- ------ ------- --------------- simpserv 00001.00001 GROUP1 1 - - (DEAD MIGRATING) > psr -g GROUP1 TMADMIN_CAT:121: No such server migg -cancel GROUP1 >boot -g GROUP1 Booting server processes... exec simpserv -A: on SITE1 ->process id_27636 ... Started. 1 process started. > psr -g GROUP1
a.out Name Queue Name Grp Name ID RqDone Ld Done Current Service ---------- ---------- -------- -- ------ ------- --------------- simpserv 00001.00001 GROUP1 1 - - ( - ) > q
To migrate transactions logs to a backup machine, complete the following steps.
TLOG
into an
ASCII file by running the following command.dumptlog [-z config] [-o offset]
[-n name] [-g groupname]
Note:
The TLOG
is
specified by the config
and offset
arguments.
Offset
defaults
to 0
and name
defaults to TLOG
. If the -g
option is chosen, only those
records for which the TMS
from groupname
is the coordinator are dumped.
filename
to the backup machine. loadtlog -m machine
ASCII_file
to read the name of the ASCII file into the existing TLOG
for the specified machine. logstart
machine
to force a warm start
of the TLOG
. TLOG
to create an entry in the transaction table in shared memory.)
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