SWITCH STREAM command
Summary
- Privileges
- System manager
- Function
- You can switch streams — parallel, ring, concatenated, GDG — to the next member at any time.
Syntax
SWITCH STREAM streamname [RESET]
Where:
| streamname | CCAJRNL, CCAJLOG, CHKPOINT, or CHKPNTS. The command is valid only for these streams. |
|---|---|
| RESET | This optional parameter causes any disabled parallel GDG members to be reopened during the switch.
Valid only when CCAJLOG or CCAJRNL are defined as a parallel stream defined with GDG members, as in the following example, which specifies two complete copies of CCAJLOG using GDGs as a base: DEFINE STREAM CCAJLOG … PARALLEL=(P1,P2) … DEFINE STREAM P1 … GDG=(D1) … DEFINE STREAM P2 … GDG=(D2) … DEFINE DATASET D1…. DEFINE DATASET D2… Note: RESET of CCAJNRL is only possible as version 8.0 of Model 204. A custom zap may be available for earlier versions. |
Usage notes
- If you specify:
- A journal stream (CCAJRNL or CCAJLOG): the currently active data set is closed and the next data set defined to the stream is opened.
- A checkpoint stream (CHKPOINT or CHKPNTS): the currently active data set in the stream is closed after the next record is written to the data set.
- If a
SWITCH STREAM CCAJRNLcommand is issued duringCHECKPOINT EXTENDED QUIESCEcommand processing, the journal is switched, a new checkpoint is issued, and the duration of the extended quiesce time-out set in CPQZSECS is reset to its maximum, original value (disregarding the already-elapsed time). - A
SWITCH STREAM CCAJRNL RESETcommand is only allowed duringCHECKPOINT EXTENDED QUIESCEcommand processing. Ie - For an extensive discussion about using the SWITCH STREAM command, see Tracking system activity (CCAJRNL, CCAAUDIT, CCAJLOG).
CHECKPOINT SET E Q CHECKPOINT SWITCH STREAM CCAJRNL RESET CHECKPOINT UNSET E Q