OGG-02803 Encountered a Data Guard role transition

告警提示其实已经很明显了
OGG-02803 Encountered a Data Guard role transition. Alter Extract to SCN 15,756,246 and restart Extract, or recreate Extract with the correct number of threads
at SCN 15,756,246.
err log：
Source Context :
SourceModule : [er.redo.ora.rtc]
SourceID : [/scratch/aime1/adestore/views/aime1_adc4150384/oggcore/OpenSys/src/app/er/redo/oracle/rtc.c]
SourceFunction : [RTC_read]
SourceLine : [2753]
ThreadBacktrace : [13] elements
: [/home/oracle/goldengate/libgglog.so(CMessageContext::AddThreadContext()+0x1e) [0x7f5981833dce]]
: [/home/oracle/goldengate/libgglog.so(CMessageFactory::CreateMessage(CSourceContext*, unsigned int, ...)+0x340) [0x7f598182eae0]]
: [/home/oracle/goldengate/libgglog.so(_MSG_ERR_ROLE_TRANSITION(CSourceContext*, long, CMessageFactory::MessageDisposition)+0x31) [0x7f5981801d5d]]
: [/home/oracle/goldengate/extract(RTC_read(char*, int*, long*, char*, short*, int, char*)+0xcc9) [0x7ffb59]]
: [/home/oracle/goldengate/extract(READ_EXTRACT_RECORD(chkpt_context_t*, short, char*, unsigned long, __std_rec_hdr*, int*, int*, long*, short, char*, short*, char
*, short*, long*, char (&) [2048])+0x18e) [0x5357ae]]
: [/home/oracle/goldengate/extract(process_extract_loop()+0x7f6) [0x5b86a6]]
: [/home/oracle/goldengate/extract(extract_main(int, char**)+0x418) [0x5b6aa8]]
: [/home/oracle/goldengate/extract(ggs::gglib::MultiThreading::MainThread::ExecMain()+0x4f) [0x6a1e2f]]
: [/home/oracle/goldengate/extract(ggs::gglib::MultiThreading::Thread::RunThread(ggs::gglib::MultiThreading::Thread::ThreadArgs*)+0x104) [0x6a2334]]
: [/home/oracle/goldengate/extract(ggs::gglib::MultiThreading::MainThread::Run(int, char**)+0x8b) [0x6a26fb]]
: [/home/oracle/goldengate/extract(main+0x3f) [0x5b643f]]
: [/lib64/libc.so.6(__libc_start_main+0xfd) [0x7f597cf37cdd]]
: [/home/oracle/goldengate/extract() [0x52ad09]]

2018-05-11 14:45:41 ERROR OGG-02803 Encountered a Data Guard role transition. Alter Extract to SCN 15,756,246 and restart Extract, or recreate Extract with the correct number of threads
at SCN 15,756,246.

GGSCI (test199) 59> alter ext1, scn 15756246
GGSCI (test199) 60> info all

Program Status Group Lag at Chkpt Time Since Chkpt

MANAGER RUNNING
EXTRACT STOPPED EXT1 00:00:00 00:00:01
REPLICAT RUNNING RXT1 00:00:00 00:00:00
GGSCI (test199) 61> start ext1 --启动进程
GGSCI (test199) 73> stats ext1 --查下状态