You must define sqlhosts network-connectivity
information for connection management of high-availability clusters. If Connection Managers,
database servers, or client applications are outside of a trusted
network, you must also create an encrypted password file for security.
To use a file other than $INFORMIXDIR/etc/sqlhosts on
a specific host, set the host's INFORMIXSQLHOSTS environment
variable to the alternative file.
- 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_2 port_2 s=6
server_3 onsoctcp host_3 port_3 s=6
- On the host of each Connection Manager and database server,
create sqlhosts file alias entries for each database
server.
For example:
#dbservername nettype hostname servicename options
server_1 onsoctcp host_1 port_1 s=6
a_server_1 onsoctcp host_1 port_4
server_2 onsoctcp host_2 port_2 s=6
a_server_2 onsoctcp host_2 port_5
server_3 onsoctcp host_3 port_3 s=6
a_server_3 onsoctcp host_3 port_6
- On the host of each Connection Manager, add a group entry
the individual entries. Add group options to the database server and
database server alias 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
my_servers group - - c=1,e=a_server_3
server_1 onsoctcp host_1 port_1 s=6,g=my_servers
a_server_1 onsoctcp host_1 port_4 g=my_servers
server_2 onsoctcp host_2 port_2 s=6,g=my_servers
a_server_2 onsoctcp host_2 port_5 g=my_servers
server_3 onsoctcp host_3 port_3 s=6,g=my_servers
a_server_3 onsoctcp host_3 port_6 g=my_servers
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.
my_servers a_server_1 user_1 my_password_1
my_servers a_server_2 user_2 my_password_2
my_servers a_server_3 user_3 my_password_3
server_1 a_server_1 user_1 my_password_1
server_2 a_server_2 user_2 my_password_2
server_3 a_server_3 user_3 my_password_3
a_server_1 a_server_1 user_1 my_password_1
a_server_2 a_server_2 user_2 my_password_2
a_server_3 a_server_3 user_3 my_password_3
- In each database server's onconfig file,
set the DBSERVERALIASES parameter to that database server's alias.
The
onconfig file entry for
server_1:
DBSERVERALIASES a_server_1
The
onconfig file
entry for
server_2:
DBSERVERALIASES a_server_2
The
onconfig file
entry for
server_3:
DBSERVERALIASES a_server_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 my_servers
SLA sla_primary_1 DBSERVERS=PRI
SLA sla_secondaries_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 my_servers
SLA sla_primary_2 DBSERVERS=PRI
SLA sla_secondaries_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
- 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
Client connection requests to @g_primary are directed
to one of the Connection Managers. If connection_manager_1 receives
the request, it uses sla_primary_1 to provide the client application
with connection information for the primary server. If connection_manager_2 receives
the request, it uses sla_primary_2 to provide the client application
with connection information for the primary server.