KIX_XA_REOPEN_THRESHOLD is an optional environment variable. It defines threshold to trigger RM reopen. Threshold is continuous XA operation failure times; XA operation is tpbegin/tpcommit/tpabort, from Tuxedo perspective. When the threshold is met, ART for CICS application servers (ARTSTRN/1, ARTATRN/1, ARTCTRN/1, ARTWTRN/1 and ARTDPL) suspend its transaction service, and then try to re-open RM to recover the failure. KIX_XA_REOPEN_THRESHOLD must be a positive value in decimal format; if it is not set, "XA error detect and RM reopen" function is not enabled.