Summary information |
|
|---|---|
Default value |
500 |
Valid values |
100 to 2147483647 |
Status |
Dynamic |
Display level |
10 |
Required role |
System Administrator |
number of dtx participants sets the total number of remote transactions that the Adaptive Server transaction coordination service can propagate and coordinate at one time. 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.
By default, Adaptive Server can coordinate 500 remote transactions. Setting number of dtx participants to a smaller number reduces the number of remote transactions that the server can manage. If no DTX participants are available, new distributed transactions will be unable to 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 larger number 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 Reused -------------- -------- ---------- --------- -------- ------ number of dtx 80 20 4.00 210 NA
If the #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.
If the #Max Ever Used value is too low, unused DTX participants may be consuming memory that could be used by other server functions. Consider reducing the value of number of dtx participants.
