About
TimesTen assigns a separate subdaemons to each database to perform operations including the following tasks:
- Manage databases.
- Loading the database into memory from a checkpoint file on disk
- Recovering the database if it needs to be recovered after loading it into memory
- Performing periodic checkpoints in the background against the active database
- Detecting and handling deadlocks. Find and break deadlocks.
- Performing data aging. Implement the aging policies of various tables.
- Writing log records to files. Flush the transaction log buffer to disk.
- Rollback transactions for abnormally terminated direct-mode applications.
- Perform required background processing for the database.
The main TimesTen daemon spawns subdaemons dynamically as they are needed.
Articles Related
How to
see them
With the ttstatus utility, you get a list of:
- the processes
- and the sub-daemons
[oracle@Exalytics-01 ~]$ ttstatus
TimesTen status report as of Fri Jun 22 13:08:21 2012
Daemon pid 30380 port 53396 instance tt1122
TimesTen server pid 30389 started on port 53397
------------------------------------------------------------------------
Data store /u01/app/oracle/product/aggregate_store/tt_aggr_storedi_tt_aggr_store
There are 12 connections to the data store
Shared Memory KEY 0x5b11c0df ID 993198086 (LOCKED)
PL/SQL Memory KEY 0x5c11c0df ID 993230855 Address 0x7fa0000000
Type PID Context Connection Name ConnID
Process 30449 0x00000000013b96c0 di_tt_aggr_store 1
Subdaemon 30384 0x0000000000a4e430 Manager 1940
Subdaemon 30384 0x0000000000aa4a70 Rollback 1939
Subdaemon 30384 0x0000000000b88c70 Deadlock Detector 1937
Subdaemon 30384 0x0000000000b9d040 Flusher 1938
Subdaemon 30384 0x0000000000bb1530 Checkpoint 1936
Subdaemon 30384 0x0000000000bc5900 Aging 1934
Subdaemon 30384 0x0000000000bd9cd0 Monitor 1935
Subdaemon 30384 0x0000000000bee0a0 Log Marker 1932
Subdaemon 30384 0x0000000000c02470 AsyncMV 1931
Subdaemon 30384 0x00007fa894040c60 IndexGC 1930
Subdaemon 30384 0x00007fa898000c20 HistGC 1933
RAM residence policy: Always
Replication policy : Manual
Cache Agent policy : Manual
PL/SQL enabled.
------------------------------------------------------------------------
Accessible by group oinstall
End of report
Configuration
Minimum and Maximum Subdaemon
You can manually specify a range of subdaemons that the daemon may spawn, by specifying a minimum and maximum.
At any point in time, one subdaemon is potentially needed for TimesTen process recovery for each failed application process that is being recovered at that time.
By default, the maximum number of subdaemons is 50.
By default, TimesTen spawns a minimum of 4 subdaemons. However, you can change these settings by assigning new values to the -minsubs and -maxsubs options in the ttendaemon.options file.