I have this pattern and it's working : <pattern>%d{HH:mm:ss} %-5p [%t] [%c{1}] [%X{amtrac.serviceName}] [%X{amtrac.method}] [%X{amtrac.clientProcessName}] [%X{identity_user_context_guid}] [%X{identity_user_context_username}] [%X{identity_user_context_partner_id}] [%X{amtrac.tx}] MESSAGE=[%m]%n</pattern> However, I would like to replace a NULL if any of the MDC is null as a default value so... <pattern>%d{HH:mm:ss} %-5p [%t] [%c{1}] [%X{amtrac.serviceName*:-NULL*}] [%X{amtrac.method*:-NULL*}] [%X{amtrac.clientProcessName*:-NULL*}] [%X{identity_user_context_guid*:-NULL*}] [%X{identity_user_context_username}] [%X{identity_user_context_partner_id}] [%X{amtrac.tx}] MESSAGE=[%m]%n</pattern> I tried it but it seems like it totally stops logging anything. Thanks in advance! -Amit Mohan