Managing HP Serviceguard Extension for SAP for Linux, December 2013

Table 27 HANA specific SGeSAP cluster package parameter settings (continued)
Pre-set value
Default
valueDescriptionParameter name
55Specifies the number of attempts for
HANA database operations and
pollings.
This parameter helps to increase the
SAP operations timeout. Set higher
values for large in-memory instances.
sgesap/hdb_global/hdb_retry_count
0 in case of (mem-) sync
replication; otherwise it is
not set.
not setSpecifies the duration of the
replication mechanism that can fail
to operate before the primary
package and so the automated
takeover mechanism becomes
temporarily disabled.
If this parameter is not set to 0, a
takeover operation of the secondary
system might cause the loss of
omitted transactions that happened
after start of the
hdb_sync_time_tolerance
interval before the primary failure
detection and instance halt.
If this parameter is not set at all,
package failover never becomes
disabled due to a synchronization
timeout.
sgesap/hdbprimary/hdb_sync_time_tolerance
0 in case of (mem-) sync
replication; otherwise it is
not set.
not setSpecifies the logfile volume that is
tolerable to become lost due to a
takeover operation.
If this parameter is not set to 0, a
takeover operation of the secondary
system might cause the loss of
committed transactions that
happened with the
hdb_sync_logpos_tolerance
logfile entries before the primary
failure detection and instance halt. If
this parameter is not set at all,
package failover never becomes
disabled due to a high volume of not
properly replicated data.
sgesap/hdbprimary/hdb_sync_logpos_tolerance
6.3.1 Dual-purpose SAP HANA configuration
To perform a Dual-purpose SAP HANA setup:
1. Open global.ini on the secondary node (node2).
The file is located in the path:
/hana/shared/<SID>/global/hdb/custom/config/global.ini
2. Deactivate preload_column_tables under system replication section.
Deactivation significantly reduces the memory consumption during replication. However, it
increases the duration, impact of a takeover, and behaves similar to a cold start of a HANA
database.
[system_replication]
preload_column_tables=false
94 Clustering SAP HANA System Replication using SGeSAP packages