Summary information |
|
|---|---|
Default value |
500 |
Valid values |
100 – 2147483647 |
Status |
Dynamic |
Display level |
10 |
Required role |
System administrator |
Configuration groups |
DTM Administration, Memory Use |
number of dtx participants sets the total number of remote transactions that the Adaptive Server transaction coordination service can propagate and coordinate simultaneously. A DTX participant is an internal memory structure that the coordination service uses to manage a remote transaction branch. As transactions are propagated to remote servers, the coordination service must obtain new DTX participants to manage those branches.
Setting number of dtx participants to a number smaller than the default reduces the number of remote transactions that the server can manage. If no DTX participants are available, new distributed transactions cannot start. In-progress distributed transactions may abort if no DTX participants are available to propagate a new remote transaction.
Setting number of dtx participants to a number larger than the default increases the number of remote transaction branches that Adaptive Server can handle, but also consumes more memory.
During a peak period, use sp_monitorconfig to examine the use of DTX participants:
sp_monitorconfig "number of dtx participants"
Usage information at date and time: Apr 22 2002 2:49PM. Name Num_free Num_active Pct_act Max_Used Reuse_cnt Instance_Name ------------------------ ---------- ---------- ------- ----------- ---------- -------------------- number of dtx 80 20 4.00 210 0 NULL
If the num_free value is zero or very low, new distributed transactions may be unable to start due to a lack of DTX participants. Consider increasing the number of dtx participants value.
A low Max_used value may indicate that unused DTX participants are consuming memory that could be used by other server functions. Consider reducing the value of number of dtx participants.
