ESTIMATE_FINAL_SYNCHRONIZATION_TIME table function

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The ESTIMATE_FINAL_SYNCHRONIZATION_TIME table function estimates the time required to complete object synchronization during migration phase transitions for IBM® i Migrate While Active.

This table function considers the number, types, and sizes of objects that need to be synchronized from the source node to the target node. It uses the system level value of the QIBM_MIGRATION_IFS_MAX_THREADS environment variable when estimating the time to migrate integrated file system (IFS) objects. It also factors in the network speed. See MIGRATION_NETWORK_BANDWIDTH table function for details.

The results are saved in a table named SYSIBMADM.MIGRATE_WHILE_ACTIVE_FINAL_SYNC with system name MWA_FINAL. It contains the same columns that this function returns. Existing data in the table is replaced. The default public authority for the table is *EXCLUDE.

Authorization: The caller must have *ALLOBJ special authority.

The schema is QSYS2.

estimate-transition

Specifies which migration phase transition to estimate.

ALL: The time required to complete all remaining migration activities is estimated. This includes preparation time, final synchronization, and any other pending migration phases needed to reach the cutover stage. This is the default.
FINAL: The time required to complete the final synchronization phase is estimated.
IMMEDIATE: The time required to transition into immediate synchronization is estimated. This estimates the duration to start immediate synchronization of Db2 Mirror replication-eligible objects (the IMMEDIATE SYNCHRONIZATION phase).
PREPARE FINAL: The time required to prepare for final synchronization is estimated. This estimates the duration of preparation activities required for migrations of all objects before entering the FINAL SYNCHRONIZATION phase.

The result of the function is a table containing rows with the format shown in the following table. All the columns are null capable.

Table 1. ESTIMATE_FINAL_SYNCHRONIZATION_TIME table function
Column Name	Data Type	Description
CAPTURE_TIME	TIMESTAMP	The timestamp when this row was generated.
TRACKING_LIST	VARCHAR(21)	IFS TRACKING LIST This row corresponds to all the integrated file system (IFS) objects that need to be migrated as described in the integrated file system tracking list (ITL). LIBRARY TRACKING LIST This row corresponds to all the library-based objects that need to be migrated as described in the library tracking list (LTL). OBJECT TRACKING LIST This row corresponds to all the library-based objects that need to be synchronized as described in the Db2® Mirror object tracking list (OTL).
OBJECT_COUNT	BIGINT	The number of synchronization operations that are needed to bring the target node "in sync" with the source node. The number returned in this column is not the number of objects that need to be synchronized. The number returned in this column factors in the number of objects to be saved and restored, and the number of operations that are not save and restore operations, but are required to fully synchronize the remaining objects on the Migrate While Active tracking lists.
DATA_SIZE	DECIMAL(15,2)	The total size of objects or sets of database file rows associated with synchronization operations, in megabytes.
ESTIMATED_TRANSFER_TIME	DECIMAL(15,2)	The estimated time required to transmit unsynchronized objects from the source node to the target node, in minutes.
ESTIMATED_OVERHEAD_TIME	DECIMAL(15,2)	The estimated additional processing time, such as the save and restore overhead, required to transmit unsynchronized objects from the source node to the target node, in minutes.
ESTIMATED_TOTAL_TIME	DECIMAL(15,2)	The total estimated time required to perform synchronization, in minutes.

Example

Estimate the length of time required to complete synchronization of objects to the target node.
```
SELECT * FROM TABLE(QSYS2.ESTIMATE_FINAL_SYNCHRONIZATION_TIME(ESTIMATE_TRANSITION => 'ALL'));
```

Compare the length of time required to complete synchronization of objects to the target node with the IFS parallel processing option set to 4 threads and to 10 threads.

-- If the environment variable already exists, use CHGENVVAR instead of ADDENVVAR
CL: QSYS/ADDENVVAR ENVVAR(QIBM_MIGRATION_IFS_MAX_THREADS) VALUE(4) LEVEL(*SYS);
SELECT * FROM TABLE(QSYS2.ESTIMATE_FINAL_SYNCHRONIZATION_TIME(ESTIMATE_TRANSITION => 'ALL'));

CL: QSYS/CHGENVVAR ENVVAR(QIBM_MIGRATION_IFS_MAX_THREADS) VALUE(10) LEVEL(*SYS);
SELECT * FROM TABLE(QSYS2.ESTIMATE_FINAL_SYNCHRONIZATION_TIME(ESTIMATE_TRANSITION => 'ALL'));