Connection Managers support Distributed
Relational Database Architecture™ (DRDA®)
connections for high-availability clusters. You must define sqlhosts network-connectivity
information for connection management of high-availability clusters
that use DRDA. If Connection Managers,
database servers, or client applications are outside of a trusted
network, you must also create an encrypted password file for security.
About this task
The Connection Manager's sqlhosts file
must contain entries for all database servers that it connects to.
To
use a file other than $INFORMIXDIR/etc/sqlhosts on
a specific host, set the host's INFORMIXSQLHOSTS environment
variable to the alternative file.
Procedure
- On the host of each Connection Manager and database server,
create sqlhosts file entries for each database
server in the cluster, and specify the
s=6 secure-port
option.For example:
#dbservername nettype hostname servicename options
server_1 onsoctcp host_1 port_1 s=6
server_2 onsoctcp host_3 port_2 s=6
server_3 onsoctcp host_5 port_3 s=6
- On the host of each Connection Manager and database server,
add DRDA alias entries. Use
a DRDA protocol for the
nettype value,
and specify the s=6 secure-port option.For
example:
#dbservername nettype hostname servicename options
server_1 onsoctcp host_1 port_1 s=6
server_2 onsoctcp host_2 port_2 s=6
server_3 onsoctcp host_3 port_3 s=6
drda_1 drsoctcp host_1 port_4 s=6
drda_2 drsoctcp host_2 port_5 s=6
drda_3 drsoctcp host_3 port_6 s=6
- On the host of each Connection Manager and database server,
create sqlhosts file alias entries for each database
server and each DRDA alias.
For example:
#dbservername nettype hostname servicename options
server_1 onsoctcp host_1 port_1 s=6
a_server_1 onsoctcp host_1 port_7
server_2 onsoctcp host_2 port_2 s=6
a_server_2 onsoctcp host_2 port_8
server_3 onsoctcp host_3 port_3 s=6
a_server_3 onsoctcp host_3 port_9
drda_1 drsoctcp host_1 port_4 s=6
a_drda_1 drsoctcp host_1 port_10
drda_2 drsoctcp host_2 port_5 s=6
a_drda_2 drsoctcp host_2 port_11
drda_3 drsoctcp host_3 port_6 s=6
a_drda_3 drsoctcp host_3 port_12
- On the host of each Connection Manager, add group entries
for the groups of database servers and DRDA entries.
Add group options to the individual entries. Use the
c=1 group-entry
option, so that connection-attempt starting points in the list of
group members is random. Use the e=last_member group-entry
option so that the entire sqlhosts is not scanned
for group members.For example:
#dbservername nettype hostname servicename options
g_servers group - - c=1,e=a_server_3
server_1 onsoctcp host_1 port_1 s=6,g=g_servers
a_server_1 onsoctcp host_1 port_7 g=g_servers
server_2 onsoctcp host_2 port_2 s=6,g=g_servers
a_server_2 onsoctcp host_2 port_8 g=g_servers
server_3 onsoctcp host_3 port_3 s=6,g=g_servers
a_server_3 onsoctcp host_3 port_9 g=g_servers
g_drda group - - c=1,e=a_drda_3
drda_1 drsoctcp host_1 port_4 s=6,g=g_drda
a_drda_1 drsoctcp host_1 port_10 g=g_drda
drda_2 drsoctcp host_2 port_5 s=6,g=g_drda
a_drda_2 drsoctcp host_2 port_11 g=g_drda
drda_3 drsoctcp host_3 port_6 s=6,g=g_drda
a_drda_3 drsoctcp host_3 port_12 g=g_drda
A
password file that is encrypted through the
onpassword utility
is required for connectivity through secure ports. The entries in
the previously shown
sqlhosts file are represented
in the following password file.
g_servers a_server_1 user_1 password_1
g_servers a_server_2 user_2 password_2
g_servers a_server_3 user_3 password_3
server_1 a_server_1 user_1 password_1
server_2 a_server_2 user_2 password_2
server_3 a_server_3 user_3 password_3
a_server_1 a_server_1 user_1 password_1
a_server_2 a_server_2 user_2 password_2
a_server_3 a_server_3 user_3 password_3
g_drda a_drda_1 user_1 password_1
g_drda a_drda_2 user_2 password_2
g_drda a_drda_3 user_3 password_3
drda_1 a_drda_1 user_1 password_1
drda_2 a_drda_2 user_2 password_2
drda_3 a_drda_3 user_3 password_3
a_drda_1 a_drda_1 user_1 password_1
a_drda_2 a_drda_2 user_2 password_2
a_drda_3 a_drda_3 user_3 password_3
- In each database server's onconfig file,
set the DBSERVERALIASES parameter to that database server's aliases.
The
onconfig file entry for
server_1:
DBSERVERALIASES a_server_1,drda_1,a_drda_1
The
onconfig file
entry for
server_2:
DBSERVERALIASES a_server_2,drda_2,a_drda_2
The
onconfig file
entry for
server_3:
DBSERVERALIASES a_server_3,drda_3,a_drda_3
- On the host of each client application, create an sqlhosts file
entry for each service-level agreement (SLA) in each Connection Manager
configuration file.
The first Connection Manager's configuration file has the following entries:
NAME connection_manager_1
CLUSTER my_cluster
{
INFORMIXSERVER g_servers,g_drda
SLA sla_primary_1 DBSERVERS=PRI
SLA sla_primary_drda_1 DBSERVERS=PRI
SLA sla_secondaries_1 DBSERVERS=SDS,HDR
SLA sla_secondaries_drda_1 DBSERVERS=SDS,HDR
FOC ORDER=ENABLED \
PRIORITY=1
}
The second Connection Manager's configuration file has the following entries:
NAME connection_manager_2
CLUSTER my_cluster
{
INFORMIXSERVER g_servers,g_drda
SLA sla_primary_2 DBSERVERS=PRI
SLA sla_primary_drda_2 DBSERVERS=PRI
SLA sla_secondaries_2 DBSERVERS=SDS,HDR
SLA sla_secondaries_drda_2 DBSERVERS=SDS,HDR
FOC ORDER=ENABLED \
PRIORITY=2
}
Add the following entries to each client application's
host
sqlhosts file:
#dbservername nettype hostname servicename options
sla_primary_1 onsoctcp cm_host_1 cm_port_1
sla_primary_2 onsoctcp cm_host_2 cm_port_2
sla_secondaries_2 onsoctcp cm_host_1 cm_port_3
sla_secondaries_2 onsoctcp cm_host_2 cm_port_4
sla_primary_1_drda drsoctcp cm_host_1 cm_port_5
sla_primary_2_drda drsoctcp cm_host_2 cm_port_6
sla_secondaries_2_drda drsoctcp cm_host_1 cm_port_7
sla_secondaries_2_drda drsoctcp cm_host_2 cm_port_8
- On the host of each client application, create sqlhosts file
group entries for each group of SLA entries, and add group options
to the SLA entries. Use the
c=1 group-entry option,
so that connection-attempt starting points in the list of group members
is random. Use the e=last_member group-entry
option so that the entire sqlhosts is not scanned
for group members.#dbservername nettype hostname servicename options
g_primary group - - c=1,e=sla_primary_2
sla_primary_1 onsoctcp cm_host_1 cm_port_1 g=g_primary
sla_primary_2 onsoctcp cm_host_2 cm_port_2 g=g_primary
g_secondaries group - - c=1,e=sla_secondaries_2
sla_secondaries_2 onsoctcp cm_host_1 cm_port_3 g=g_secondaries
sla_secondaries_2 onsoctcp cm_host_2 cm_port_4 g=g_secondaries
g_primary_drda group - - c=1,e=sla_primary_2_drda
sla_primary_1_drda drsoctcp cm_host_1 cm_port_5 g=g_primary_drda
sla_primary_2_drda drsoctcp cm_host_2 cm_port_6 g=g_primary_drda
g_secondaries_drda group - - c=1,e=sla_secondaries_2_drda
sla_secondaries_2_drda drsoctcp cm_host_1 cm_port_7 g=g_secondaries_drda
sla_secondaries_2_drda drsoctcp cm_host_2 cm_port_8 g=g_secondaries_drda
Results
Client connection requests to @g_primary_drda are
sent by drsoctcp protocol to one of the Connection Managers.
If connection_manager_1 receives the request, it uses sla_primary_1_drda to
provide the client application with connection information for the
primary server. If connection_manager_2 receives the request,
it uses sla_primary_2_drda to provide the client application
with connection information for the primary server.