Re: Need help with standby database REAL TIME APPLY

From: Neil Chandler <neil_chandler_at_hotmail.com>
Date: Tue, 28 Jul 2020 15:02:50 +0000
Message-ID: <DB7PR10MB20906306478542BA9546399185730_at_DB7PR10MB2090.EURPRD10.PROD.OUTLOOK.COM>



Sandra,

What's the thread for groups 22/23/24/25 and 32/33/34/35 as the latest output shows it as blank (unless you have "break on thread#" in your SQL*Plus session). You have to specify it explicitly in each command:

alter database add standby logfile thread 1 group 22 '.......' size 1024M; alter database add standby logfile thread 1 group 23 '.......' size 1024M;

alter database add standby logfile thread 2 group 32 '.......' size 1024M; etc

On both the primary and the standby databases.

Neil Chandler
https://chandlerdba.com/2019/01/03/data-guard-unexpected-lag/



From: oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> on behalf of Sandra Becker <sbecker6925_at_gmail.com> Sent: 28 July 2020 15:30
To: Andrew Kerber <andrew.kerber_at_gmail.com> Cc: Leng Burgess <lkaing_at_gmail.com>; oracle-l <oracle-l_at_freelists.org> Subject: Re: Need help with standby database REAL TIME APPLY

I have 5 SRLs for each thread, but the alert log still says "No standby redo logfiles available for T-2".

SELECT
        thread#,group#, sequence#, used, archived, status, ROUND(bytes/1024/1024) mbytes, last_time FROM v$standby_log
ORDER BY

        thread#,
        group#;

THREAD#  GROUP#  SEQUENCE#       USED ARC STATUS                        MBYTES LAST_TIME
------- ------- ---------- ---------- --- ------------------------- ---------- -------------------
      1      21          0          0 YES UNASSIGNED                      1024
             22          0          0 YES UNASSIGNED                      1024
             23          0          0 YES UNASSIGNED                      1024
             24          0          0 YES UNASSIGNED                      1024
             25          0          0 YES UNASSIGNED                      1024

      2      31          0          0 YES UNASSIGNED                      1024
             32          0          0 YES UNASSIGNED                      1024
             33          0          0 YES UNASSIGNED                      1024
             34          0          0 YES UNASSIGNED                      1024
             35          0          0 YES UNASSIGNED                      1024

On Tue, Jul 28, 2020 at 8:08 AM Sandra Becker <sbecker6925_at_gmail.com<mailto:sbecker6925_at_gmail.com>> wrote: Ok, redoing the SRLs.

Sandy

On Tue, Jul 28, 2020 at 7:45 AM Andrew Kerber <andrew.kerber_at_gmail.com<mailto:andrew.kerber_at_gmail.com>> wrote: You need one more srl per thread on the standby than primary redo logs. Ie, if you have 4 redo logs per thread on the primary you need at least 5 standby redo logs per thread.

On Tue, Jul 28, 2020 at 8:41 AM Sandra Becker <sbecker6925_at_gmail.com<mailto:sbecker6925_at_gmail.com>> wrote: I added 6 more standby redo log groups to thread 2. Didn't make any difference. Still seeing the message "RFS[8]: No standby redo logfiles available for T-2". Today's dgmgrl output:  Database Role: Physical standby database   Primary Database: UTILS

  Ready for Switchover: No
  Ready for Failover: Yes (Primary Running)

  Capacity Information:

    Database   Instances        Threads
    UTILS      1                2
    UTILS_DB1  1                1

    Warning: the target standby has fewer instances than the     primary database, this may impact application performance

  Temporary Tablespace File Information:     UTILS TEMP Files: 1
    UTILS_DB1 TEMP Files: 1

  Flashback Database Status:
    UTILS: Off
    UTILS_DB1: Off

  Data file Online Move in Progress:
    UTILS: No
    UTILS_DB1: No

  Standby Apply-Related Information:

    Apply State:      Running
    Apply Lag:        2 minutes 9 seconds (computed 15 seconds ago)
    Apply Delay:      0 minutes

  Transport-Related Information:
    Transport On:      Yes
    Gap Status:        No Gap
    Transport Lag:     2 minutes 9 seconds (computed 15 seconds ago)
    Transport Status: Success

  Log Files Cleared:
    UTILS Standby Redo Log Files: Cleared     UTILS_DB1 Online Redo Log Files: Cleared     UTILS_DB1 Standby Redo Log Files: Available

  Current Log File Groups Configuration:     Thread # Online Redo Log Groups Standby Redo Log Groups Status

(UTILS) (UTILS_DB1)

    0         22                      0                       Insufficient SRLs
    Warning: standby redo logs not configured for thread 0 on UTILS_DB1
    1         2                       4                       Sufficient SRLs

  Future Log File Groups Configuration:
    Thread # Online Redo Log Groups Standby Redo Log Groups Status

(UTILS_DB1) (UTILS)

    1         3                       4                       Sufficient SRLs

  Current Configuration Log File Sizes:
    Thread #   Smallest Online Redo      Smallest Standby Redo
               Log File Size             Log File Size
               (UTILS)                   (UTILS_DB1)
    1          1024 MBytes               1024 MBytes

  Future Configuration Log File Sizes:
    Thread #   Smallest Online Redo      Smallest Standby Redo
               Log File Size             Log File Size
               (UTILS_DB1)               (UTILS)
    1          1024 MBytes               1024 MBytes

  Apply-Related Property Settings:
    Property                        UTILS Value              UTILS_DB1 Value
    DelayMins                       0                        0
    ApplyParallel                   AUTO                     AUTO

  Transport-Related Property Settings:
    Property                        UTILS Value              UTILS_DB1 Value
    LogXptMode                      ASYNC                    ASYNC
    RedoRoutes                      <empty>                  <empty>
    Dependency                      <empty>                  <empty>
    DelayMins                       0                        0
    Binding                         optional                 optional
    MaxFailure                      0                        0
    MaxConnections                  1                        1
    ReopenSecs                      300                      300
    NetTimeout                      30                       30
    RedoCompression                 DISABLE                  DISABLE
    LogShipping                     ON                       ON

  Automatic Diagnostic Repository Errors:
    Error                       UTILS    UTILS_DB1
    No logging operation        NO       NO
    Control file corruptions    NO       NO
    SRL Group Unavailable       NO       NO
    System data file missing    NO       NO
    System data file corrupted  NO       NO
    System data file offline    NO       NO
    User data file missing      NO       NO
    User data file corrupted    NO       NO
    User data file offline      NO       NO

Sandy

On Mon, Jul 27, 2020 at 10:45 PM Leng Burgess <lkaing_at_gmail.com<mailto:lkaing_at_gmail.com>> wrote: Hi Sandra,

Given that you have 2 primary instances (each with 4 redo groups), you need to create 2x4=8+2 standby redo logs.

So try adding 6 more add more standby redo log groups.

Please let me know how it goes.

Cheers,

Leng.

On 28 Jul 2020, at 7:10 am, Sandra Becker <sbecker6925_at_gmail.com<mailto:sbecker6925_at_gmail.com>> wrote:

OS: RHEL6
Oracle: EE 12.1.0.2
Primary: RAC
Standby: Single instance

We are moving our 2-node RAC database to a single instance primary-standby configuration. We have only 1 instance running; we are not using both nodes. I am trying to create the first standby and ensure it's syncing with Real Time Apply before proceeding. I have created the standby database, but can't seem to manage to get it to actually use REAL TIME APPLY. It says it started managed recover with Real Time Apply in the alert log, but then I see it's not using the SRLs I added. I've looked at several blogs and docs in MOS as well, and still have not been able to get it to recognize the SRLs. It will ship and apply the log if we do a log switch, but our DR policy is to use RTA. I created SRLs without the THREAD parameter and it created them for thread 0. That didn't work for me so I created SRLs for thread 1 and 2. The alert log says there are not standby redo logfiles available for T-2. I also ensured the size matched the primary online redo. Do I need more SRLs for T-2 and none for T-0 and T-1? Completely lost and confused at this point. I could really use some help figuring out where I went wrong.

Primary Queries
 select dest_id, status, recovery_mode, dest_name from v$archive_dest_status where dest_id = 2;    DEST_ID STATUS RECOVERY_MODE DEST_NAME

---------- ---------- ----------------------- ------------------
         2 VALID      MANAGED REAL TIME APPLY LOG_ARCHIVE_DEST_2

SELECT
        l.inst_id, l.group#, l.thread#, l.sequence#, l.members, l.bytes/1024/1024 mbytes, l.archived, l.status, l.first_time
FROM gv$log l
ORDER BY
        l.thread#,
        l.group#

/

INST_ID GROUP# THREAD# SEQUENCE# MBR MBYTES ARC STATUS FIRST_TIME

------- ------- ------- ---------- --- ---------- --- ---------- -------------------
      2      10       1      29353   2       1024 YES INACTIVE   2018-10-06 16:02:40
      2      11              29356   2       1024 YES INACTIVE   2018-10-06 22:31:22
      2      12              29354   2       1024 YES INACTIVE   2018-10-06 22:30:16
      2      13       2     187312   2       1024 NO  CURRENT    2020-07-27 20:30:25
      2      14             187310   2       1024 YES INACTIVE   2020-07-27 20:14:09
      2      15             187311   2       1024 YES INACTIVE   2020-07-27 20:15:54


Standby Queries
select thread#, group#, sequence#, round(bytes/1024/1024) bytes, status from v$standby_log; THREAD# GROUP# SEQUENCE# BYTES STATUS ------- ------- ---------- ---------- -----------

      0      10          0       1024 UNASSIGNED
      0      11          0       1024 UNASSIGNED
      0      12          0       1024 UNASSIGNED
      0      13          0       1024 UNASSIGNED
      1      20          0       1024 UNASSIGNED
      1      21          0       1024 UNASSIGNED
      1      22          0       1024 UNASSIGNED
      1      23          0       1024 UNASSIGNED
      2      24          0       1024 UNASSIGNED
      2      25          0       1024 UNASSIGNED
      2      26          0       1024 UNASSIGNED
      2      27          0       1024 UNASSIGNED

dgmgrl
DGMGRL> validate database 'UTILS_DB1';

  Database Role: Physical standby database   Primary Database: UTILS

  Ready for Switchover: No
  Ready for Failover: Yes (Primary Running)

  Capacity Information:

    Database   Instances        Threads
    UTILS      1                2
    UTILS_DB1  1                1

    Warning: the target standby has fewer instances than the     primary database, this may impact application performance

  Flashback Database Status:
    UTILS: Off
    UTILS_DB1: Off

  Standby Apply-Related Information:

    Apply State:      Running
    Apply Lag:        27 minutes 18 seconds (computed 56 seconds ago)
    Apply Delay:      0 minutes

  Current Log File Groups Configuration:     Thread # Online Redo Log Groups Standby Redo Log Groups Status

(UTILS) (UTILS_DB1)

    0         12                      4                       Insufficient SRLs
    1         3                       0                       Insufficient SRLs
    Warning: standby redo logs not configured for thread 1 on UTILS_DB1

Alert Log Excerpt
Starting background process MRP0
Mon Jul 27 20:28:50 2020
MRP0 started with pid=28, OS id=423445
Mon Jul 27 20:28:50 2020
MRP0: Background Managed Standby Recovery process started (UTILS_DB1) Mon Jul 27 20:28:55 2020
 Started logmerger process
Mon Jul 27 20:28:55 2020
Managed Standby Recovery starting Real Time Apply Mon Jul 27 20:28:55 2020
Parallel Media Recovery started with 10 slaves Mon Jul 27 20:28:55 2020
Waiting for all non-current ORLs to be archived... Mon Jul 27 20:28:55 2020
All non-current ORLs have been archived. Mon Jul 27 20:28:55 2020
Media Recovery Waiting for thread 2 sequence 187311 (in transit) Completed: alter database recover managed standby database disconnect Mon Jul 27 20:29:43 2020

.
.
.

Primary database is in MAXIMUM PERFORMANCE mode
RFS[8]: Assigned to RFS process (PID:423753)
RFS[8]: No standby redo logfiles available for T-2
RFS[8]: Opened log for thread 2 sequence 187312 dbid 3599144416 branch 818022052
Mon Jul 27 20:30:27 2020
Media Recovery Waiting for thread 2 sequence 187312 (in transit)
--
Sandy B.




--
Sandy B.



--
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'


--
Sandy B.



--
Sandy B.


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Received on Tue Jul 28 2020 - 17:02:50 CEST

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