Dataguard Doubt
hi all
first this is not an problem i am reporting, rather an doubt i have as i am experimenting dataguard in oracle 10g.
I have setup and primary and standby database and configured dataguard, switchover and failovers are working fine.
if my primary database is PRIM and standby database is STAN, after a failover and role change.
how does the client application or clients know and atuomatically adapt to the change. hope i have framed the question clearly.
thanks
You have several ways to tell the clients / application about the role change :
1. User Load balancer to control the application / clients traffic to the current primary instance.
2. Write script that changes DNS / Hosts entry to point to the current primary instance.
3. User Services as mentioned above.
Oded Raz
[www.dbsnaps.com]
[www.orbiumsoftware.com]
Similar Messages
-
Dear all,
Please help me regarding this i am very much confused.....
I had couple of doubts in dataguard concepts.
1)When archive log is transferred from primary to standby ,
a.Whether DBWR will be in active state or not in standby server.To write the contents in the archived redo log files which came from the primary to the datafiles of the standby server.
b.I am using online redo logs in the standby server not standby redo logs , whether online redologs in the standby server will have any effect in shipping of redologs from the primary database,
c. In my standby database online redo logs state is changing between CLEARING AND CLEARING CURRENT.How standby server redologs will change it state,
Regards,
Vamsi.Hi again,
They are not used in a physical standby database. They exist in order to be used in a case of opening the standby database read-write (failover/snapshot standby). Here what documentation says:
Online redo logs
Every instance of an Oracle primary database and logical standby database has an associated online redo log to protect the database in case of an instance failure. Physical standby databases do not have an associated online redo log, because physical standby databases are never opened for read/write I/O; changes are not made to the database and redo data is not generated.
Create an Online Redo Log on the Standby Database
Although this step is optional, Oracle recommends that an online redo log be created when a standby database is created. By following this best practice, a standby database will be ready to quickly transition to the primary database role.
... -
Doubt on dataguard maximum perfomance mode
HI Gurus ,
We have a dataguard environment configured in 12.1.0.2.0 on OEL 5.6. Dataguard is configured in maximum performance using following congiguration ,
18:26:26 SQL> show parameter log_archive_dest_2
NAME TYPE VALUE
log_archive_dest_2 string service=TGOID NOAFFIRM LGWR ASYNC COMPRESSION=ENABLE VALID_FOR=(ALL_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=TGOID
Here I used LGWR ASYNC and enabled real time apply at my standby using ,
SQl> alter database recover managed standby database using current logfile disconnect;
Here are my doubts ,
1. If we enable real time apply ,the changes will reflect at standby when a commit happens at primary. is it correct ?
But here I can't see that behavior , the changes are getting applied to standby only when I make a log switch.(as in the case of ARCH transport mode )
2. So if I wish to get the changes done at standby when a commit happens at primary, is I need to set the following ?
First ,
alter system set log_archive_dest_2=service=TGOID AFFIRM LGWR SYNC COMPRESSION=ENABLE VALID_FOR=(ALL_LOGFILES,PRIMARY_ROLE)DB_UNIQUE_NAME=TGOID scope=both;
Secondly,
ALTER DATABASE SET STANDBY DATABASE TO MAXIMIZE PROTECTION/MAXIMIZE AVAILABILITY .
is it correct ?
3. If its correct what is the advantage of using lgwr async in maximum performance ? then what is meant by real time apply in maximum performance ?
Thanks and regards,
Mahihttp://docs.oracle.com/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
Step 2 Determine the appropriate number of standby redo log file groups
(maximum number of logfiles for each thread + 1) * maximum number of threads -
Doubt regarding REAL time redo apply in Dataguard
Friends, how to check whether 'REAL TIME REDO APPLY' is configured in my dataguard configuration. If it is not 'on' , how to enable 'REAL TIME REDO APPLY' on using dataguard broker.
Thanks in advance.918868 wrote:
Friends, how to check whether 'REAL TIME REDO APPLY' is configured in my dataguard configuration. If it is not 'on' , how to enable 'REAL TIME REDO APPLY' on using dataguard broker.
Thanks in advance.You have to check the client process whether it is LGWR or ARCH process. The CLIENT PROCESS refers to corresponding primary database process.
SQL> SELECT THREAD#,SEQUENCE#,PROCESS,CLIENT_PROCESS,STATUS,BLOCK#,BLOCKS FROM V$MANAGED_STANDBY;
THREAD# SEQUENCE# PROCESS CLIENT_P STATUS BLOCK# BLOCKS
0 0 ARCH ARCH CONNECTED 0 0
0 0 ARCH ARCH CONNECTED 0 0
0 0 ARCH ARCH CONNECTED 0 0
0 0 ARCH ARCH CONNECTED 0 0
1 149 ARCH ARCH CLOSING 61440 1244
0 0 RFS N/A IDLE 0 0
"1 150 RFS LGWR IDLE 8910 1"
1 150 MRP0 N/A APPLYING_LOG 8910 204800 -
is it possible to configure more than one observer (dataguard) for particular primary and physical standby database?
or some other options to protect observer? what else we have to do to protect/ unplanned shutdown of observer server machine?
oracle version 11gR2 , operating system OEL 5
Thanks and Regards,
RajeshDear 791622,
Please see;
http://www.trivadis.com/uploads/tx_cabagdownloadarea/te_dg_observer_doag-mnb2_02.pdf
http://blogs.oracle.com/AlejandroVargas/gems/DataGuardBrokerandobserverst.pdf
http://www.orafaq.com/wiki/Data_Guard_implementation_for_Oracle_10gR2#DATAGUARD_OBSERVER_:
+"+
+DATAGUARD OBSERVER :+
+Observer is a utility that is available with the dataguard. Its basic purpose is to keep the database available to the clients all the time. It is started on a separate location other than Primary and Standby locations. After starting the observer, it starts watching continuously both the sites. Whenever the PRIMARY database fails due to any reason and the connection between the PRIMARY site and the observer breaks, the observer waits for a certain time which is set up during setting the broker configuration. When this time passes, the observer automatically starts the failover process. As a result, the Physical Standby database is converted to PRIMARY database. After this failover, the users again connect to the database. This connection redirects them automatically to the new PRIMARY database.+
+"+
As far as i know, there can be only one observer for a single data guard broker configuration with the fast start failover option. Protection of the observer client or the box can be achieved on system level.
Regards.
Ogan -
Hi,
Oracle Version :10.2.0.1
Operating system:Windows Xp
Please help me what is the difference between these two queries.
select
substr(local.name,1,50) "Archive Name",
case when remote.sequence# is null then 'NOT TRANSMITTED'
else 'transmitted'
end,
local.sequence#,
local.thread#
from
(select * from v$archived_log where dest_id = 1) local
left join
(select * from v$archived_log where dest_id = 2) remote
on local.sequence# = remote.sequence# and
local.thread# = remote.thread#
order by local.sequence#;
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 7 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 8 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 9 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 10 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 11 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 12 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 13 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 14 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 15 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 16 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 17 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 18 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 19 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 20 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 21 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 22 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 23 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 24 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 25 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 26 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 27 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 28 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 29 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 30 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 31 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 32 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 33 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 34 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 35 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 36 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 37 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 38 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 39 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 40 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 41 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 42 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 43 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 44 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 45 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 46 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 47 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 48 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 49 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 50 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 51 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 52 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 53 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 54 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 55 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 56 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 57 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 58 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 59 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 60 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 61 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 62 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 63 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 64 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 65 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 66 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 67 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 68 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 69 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 70 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 71 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 72 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 73 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 74 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 75 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 76 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 77 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 78 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 79 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 80 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 81 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 82 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 83 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 84 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 85 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 86 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 87 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 88 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 89 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 90 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 91 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 92 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 93 1
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 94 1
Archive Name CASEWHENREMOTE. SEQUENCE# THREAD#
E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASA transmitted 95 1
SQL> select sequence#, applied from v$archived_log;
SEQUENCE# APP
5 NO
6 NO
7 NO
8 NO
9 NO
10 NO
11 NO
12 NO
7 NO
12 NO
13 NO
SEQUENCE# APP
10 NO
11 NO
6 NO
5 NO
9 NO
8 NO
13 YES
14 NO
14 YES
15 NO
16 NO
SEQUENCE# APP
17 NO
18 NO
15 NO
16 NO
17 NO
18 YES
19 NO
19 YES
20 YES
20 NO
21 NO
SEQUENCE# APP
22 NO
23 NO
24 NO
25 NO
25 YES
21 NO
24 NO
23 NO
22 NO
26 NO
26 YES
SEQUENCE# APP
27 YES
27 NO
28 YES
28 NO
29 NO
30 NO
31 NO
32 NO
33 NO
34 NO
35 NO
SEQUENCE# APP
36 NO
37 NO
38 NO
39 NO
40 NO
41 NO
29 NO
30 NO
31 NO
32 NO
34 NO
SEQUENCE# APP
33 NO
36 YES
35 NO
37 NO
39 NO
41 YES
38 NO
40 NO
42 NO
42 YES
43 YES
SEQUENCE# APP
43 NO
44 NO
44 YES
45 YES
45 NO
46 YES
46 NO
47 NO
48 NO
49 NO
50 NO
SEQUENCE# APP
51 NO
52 NO
53 NO
54 NO
55 NO
56 NO
57 NO
47 NO
48 NO
50 NO
51 NO
SEQUENCE# APP
49 YES
54 NO
52 NO
53 NO
55 NO
57 YES
56 NO
58 NO
58 YES
59 NO
60 NO
SEQUENCE# APP
61 NO
62 NO
63 NO
64 NO
65 NO
66 NO
59 NO
60 NO
61 NO
62 YES
63 NO
SEQUENCE# APP
66 YES
65 NO
64 NO
67 NO
67 YES
68 YES
68 NO
69 YES
69 NO
70 YES
70 NO
SEQUENCE# APP
71 NO
71 YES
72 YES
72 NO
73 NO
73 YES
74 NO
75 NO
76 NO
77 NO
78 NO
SEQUENCE# APP
79 NO
80 NO
81 NO
82 NO
83 NO
84 NO
85 NO
86 NO
87 NO
88 NO
89 NO
SEQUENCE# APP
90 NO
91 NO
92 NO
93 NO
94 NO
95 NO
74 NO
76 NO
75 NO
77 NO
78 NO
SEQUENCE# APP
79 NO
80 NO
81 NO
84 NO
85 NO
86 NO
82 YES
87 NO
89 YES
91 NO
90 NO
SEQUENCE# APP
88 NO
93 NO
94 NO
92 NO
83 YES
95 YES
182 rows selected.Thanks & Regards,
Poorna.Hi,
Here is the output for your query
SQL> select dest_id, name, sequence#, archived, applied from v$archived_log order by sequence#;
DEST_ID NAME SEQUENCE# ARC APP
84 YES NO
2 poorstand 84 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_85_696773304.ARC 85 YES NO
2 poorstand 85 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_86_696773304.ARC 86 YES NO
2 poorstand 86 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_87_696773304.ARC 87 YES NO
DEST_ID NAME SEQUENCE# ARC APP
2 poorstand 87 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_88_696773304.ARC 88 YES NO
2 poorstand 88 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_89_696773304.ARC 89 YES NO
2 poorstand 89 YES YES
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_90_696773304.ARC 90 YES NO
2 poorstand 90 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_91_696773304.ARC 91 YES NO
2 poorstand 91 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_92_696773304.ARC 92 YES NO
2 poorstand 92 YES NO
DEST_ID NAME SEQUENCE# ARC APP
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_93_696773304.ARC 93 YES NO
2 poorstand 93 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_94_696773304.ARC 94 YES NO
2 poorstand 94 YES NO
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_95_696773304.ARC 95 YES NO
2 poorstand 95 YES YES
1 E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\PRASAD\ARCHIVELOG\1_96_696773304.ARC 96 YES NO
183 rows selected. -
Dear all,
Please help me regarding this i am very much confused.....
I had couple of doubts in dataguard concepts.
1)When archive log is transferred from primary to standby ,
a.Whether DBWR will be in active state or not in standby server.To write the contents in the archived redo log files which came from the primary to the datafiles of the standby server.
b.I am using online redo logs in the standby server not standby redo logs , whether online redologs in the standby server will have any effect in shipping of redologs from the primary database,
c. In my standby database online redo logs state is changing between CLEARING AND CLEARING CURRENT.How standby server redologs will change it state,
Regards,
Vamsi.Hi Vamsi,
In a case you use standby redo logs on standby;
RFS process reads redo stream and writes to standby redo logs.
ARCH process on the standby archives standby redologs into archivedlogs.
MRP process reads standby redo logs or archived log (depending on configuration) into the buffer cache. (shortly!)
DBWR writes modified blocks from buffer cache to disk.
You cannot say "I am using online redo logs in the standby server not standby redo logs" You can choose using or not using SRLs. If you don't use SRL on the standby, redo stream will be directly written to archived logs. Online redologs are out of this scope.
Online redo logs are not used in a physical standby database. They exist in order to be used in a case of opening the standby database read-write (failover/snapshot standby). Here what documentation says:
Online redo logs
Every instance of an Oracle primary database and logical standby database has an associated online redo log to protect the database in case of an instance failure. Physical standby databases do not have an associated online redo log, because physical standby databases are never opened for read/write I/O; changes are not made to the database and redo data is not generated.
+...+
Create an Online Redo Log on the Standby Database
Although this step is optional, Oracle recommends that an online redo log be created when a standby database is created. By following this best practice, a standby database will be ready to quickly transition to the primary database role.
+...+ -
Few errror/doubts in Primary and Standby server - Need Help
Hi All,
I am having below doubts/errors. I need help to solve all the below questions.
I configured Dataguard successfully. Now the sync is upto date using the below parameters (using 11g):
at primary:
log_archive_dest_1=
log_archive_dest_2='SERVICE=standby.123 arch'
standby_file_management=auto
at sandby:
log_archive_dest_1=
standby_file_management=auto
Still i face below messages in the alertliog. Can anybody clearly explain me all the points.
Primary:
ORA-1652: unable to extend temp segment by 640 in tablespace NEWTEMP
I get this error when my archvie destination got filled up, later we released the enough space, the archived are generating. Still i see this message once in between. Need to solve this.
Primary:
Checkpoint not complete ( i see this message very often, want to get rid of this)
standby:
kcrrvslf: active RFS archival for log thread 1 sequence (sometimes i see this KCRRVSLF)
standby:
check that the CONTROL_FILE_RECORD_KEEP_TIME initialization parameter is defined to a value that is sufficiently large enough to maintain afequate log switch information to resolve archivelog gaps. (also get this message in between the alertlog file in standby)
Standby:
FAL[client]: Error fetching gap sequence, no FAL server specified (this is very often message. How to remove this, what needs to be added. Do i need to add the below parameters)
FAL_CLIENT
FAL_SERVER
Thanks in advance.
Pas Moh
[email protected]Pas Moh wrote:
Hi All,
I am having below doubts/errors. I need help to solve all the below questions.
I configured Dataguard successfully. Now the sync is upto date using the below parameters (using 11g):
at primary:
log_archive_dest_1=
log_archive_dest_2='SERVICE=standby.123 arch'
standby_file_management=auto
at sandby:
log_archive_dest_1=
standby_file_management=auto
Still i face below messages in the alertliog. Can anybody clearly explain me all the points.
Primary:
ORA-1652: unable to extend temp segment by 640 in tablespace NEWTEMP
I get this error when my archvie destination got filled up, later we released the enough space, the archived are generating. Still i see this message once in between. Need to solve this.This error has absolutely nothing to do with the handling of archive logs, the status of archivelog destination, or primary/standby. Any relation you thought you saw was pure coincidence.
>
>
Primary:
Checkpoint not complete ( i see this message very often, want to get rid of this)
Here is the very first hit I got when I googled "oracle checkpoint not complete". Tom says it better than I would have.
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:69012348056
standby:
kcrrvslf: active RFS archival for log thread 1 sequence (sometimes i see this KCRRVSLF)
A quick google of that one, and it looks like it is not even an error, but rather simply an informative
>
standby:
check that the CONTROL_FILE_RECORD_KEEP_TIME initialization parameter is defined to a value that is sufficiently large enough to maintain afequate log switch information to resolve archivelog gaps. (also get this message in between the alertlog file in standby)
In that case I would check that the CONTROL_FILE_RECORD_KEEP_TIME initialization parameter is defined to a value that is sufficiently large enough to maintain adequate log switch information to resolve archivelog gaps.
How big is that? Well, at least bigger than it is now. Beyond that, it would have to be "large enough to maintain adequate log switch information to resolve archivelog gaps" Just play with it until you get the result you want.
>
Standby:
FAL[client]: Error fetching gap sequence, no FAL server specified (this is very often message. How to remove this, what needs to be added. Do i need to add the below parameters)
FAL_CLIENT
FAL_SERVER
Thanks in advance.
Pas Moh
[email protected] -
Upgrade of database in Dataguard Configuration
Hi,
I have few doubts regarding upgrading of database in in a dataguard configuration. Could someone please help me out.
- How does upgrade happen in dataguard configuration?
- Is that we have to install only different OH in both? And once the catupgrade script is run on primary, it will automatically upgrade standby as well?
- Or is that we have to upgrade both separately? i.e, standby first and then primary or vice versa
- Can we reduce downtime by breaking the dataguard config. Do a switchover and make secondary as primary and upgrade primary first?
And once the upgrade is completed in primary, bring it up and later upgrade the standby. And later once the upgrade is completed on standby, synch both primary and standby.
Please share your ideas and thoughts!
Thanks!First of all, -steps may differ regarding the upgrade versions but- my post with the following link would help you clarify the concept.
http://emrebaransel.blogspot.com/2009/02/10204-upgrade-with-dataguard.html
user1982050 wrote:
Hi,
I have few doubts regarding upgrading of database in in a dataguard configuration. Could someone please help me out.
- How does upgrade happen in dataguard configuration?First you patch the Oracle binaries on both primary and standby. Then open dataguard services and upgrade the primary database, standby will update itself already. -
V$archived noy sync in Dataguard
Hi,
My question is about a doubt that I had y my Dataguard.
Few days ago I did a scn incremental restore in order to sync Primary and Standby instances, the problem is v$archived_log is not updated. Let me show you
Primary:
select max(sequence#), to_char(next_time,'DD-MON-YY:HH24:MI:SS'), applied from v$archived_log group by to_char(next_time,'DD-MON-YY:HH24:MI:SS'), applied order by 1 desc
923426 17-FEB-13:07:16:38 NO
SQL> select max(sequence#) from v$archived_log where applied='YES';
MAX(SEQUENCE#)
915252
Standby:
select max(sequence#), to_char(next_time,'DD-MON-YY:HH24:MI:SS'), applied from v$archived_log group by to_char(next_time,'DD-MON-YY:HH24:MI:SS'), applied order by 1 desc
923426 17-FEB-13:07:16:38 YES
When I do automatic recover the gap is:
Fetching gap sequence in thread 1, gap sequence 923427-923526
My question is why I have different values on that queries?
Thanks a lot!
Edited by: 970676 on Feb 21, 2013 4:31 PMHello;
If I understand the question correctly its because of how you query v$archived_log. The max(sequence#) hurts the query because it does not allow you see the different values of DEST_ID.
Try changing the query to include DEST_ID and use WHERE sysdate > -1 ( on one of the date columns ) to see a smaller range.
clear screen
set linesize 100
column STANDBY format a20
column applied format a10
SELECT
name as STANDBY,
SEQUENCE#,
applied,
completion_time
from
v$archived_log
WHERE
DEST_ID = 2 AND NEXT_TIME > SYSDATE -1;The try this query from your Primary :
http://www.visi.com/~mseberg/data_guard/monitor_data_guard_transport.html
Best Regards
mseberg
Edited by: mseberg on Feb 21, 2013 6:49 PM -
hello,
I read various Oracle documents, guides and metalink notes but I still have some doubts. Perhaps I missed something.
starting env: dataguard (manual config, without broker) env with primary and physical standby in 11.2.0.1 on Linux x86_64
I don't want to go with rolling upgrades or similar; I'm on a test environment and also for production I can tolerate some downtime during the week end.
My upgrade scenario is to install sw in new oracle_home as recommended.
One note: the link provided in note 884522.1 gives a file for preupgrade (utlu112i.sql) that is not current ... I had to make a clean install of 11.2.0.2 and get the file provided inside rdbms/adin directory....
I start runInstaller with primary DB open and physical in mount with managed recovery and in sync
I install new binaries and then complete the dbua step (100% without errors)
I only had to change my log_archive_dest_2 that was
service=TESDB1DR ASYNC DB_UNIQUE_NAME=TESDB1DR VALID_FOR=(primary_role, online_logfile) COMPRESSION=ENABLE
and worked in 11.2.01. but dbua complained about syntax and so I had to change in:
service=TESDB1DR ASYNC DB_UNIQUE_NAME=TESDB1DR VALID_FOR=(online_logfiles,primary_role) COMPRESSION=ENABLE
Now I have my primary db in new version.
dbua didn't update the tnsnames.ora, so I get this on primary alert.log
Thu Nov 04 15:25:33 2010
Error 12154 received logging on to the standby
PING[ARC2]: Heartbeat failed to connect to standby 'TESDB1DR'. Error is 12154.
while at the end of upgrade, on standby alert.log I got:
TNS-00507: Connection closed
nt secondary err code: 0
nt OS err code: 0
Error 12537 received logging on to the standby
FAL[client, USER]: Error 12537 connecting to TESDB1 for fetching gap sequence
Errors in file /app/oracle/diag/rdbms/tesdb1dr/TESDB1DR/trace/TESDB1DR_pr00_21338.trc:
ORA-12537: TNS:connection closed
Errors in file /app/oracle/diag/rdbms/tesdb1dr/TESDB1DR/trace/TESDB1DR_pr00_21338.trc:
ORA-12537: TNS:connection closed
Thu Nov 04 13:23:12 2010
What are the steps to do at standby? The same as in primary:
1) install binaries for 11.2.0.2
2) upgrade db
and only at the end
3) modify parameters on both instances tnsnames.ora so that they are able again to communicate
Can the standby db stay in mount + recovery mode while upgrading?
I hope I have not to refresh the whole standby....
Thanks for suggestions,
GianlucaWhat do you mean by "Do I have to manually update my .ora files?" and where Primary or Standby?When on standby I select install software only, I get a new $ORACLE_HOME/network/admin that is empty
So I presume I have to copy my 11.2.0.1 tnsnames.ora and listener.ora to the new path
And to change inside my listener.ora the line
(ORACLE_HOME = /app/oracle/product/11.2.0/dbhome_1)
matching now
(ORACLE_HOME = /app/oracle/product/11.2.0/dbhome_2)
at least for the instances I want to upgrade (if more than one)
Also, I noticed that upgrading the primary with dbua, it got as a result this kind of "strange" tnsnames.ora:
# tnsnames.ora Network Configuration File: /app/oracle/product/11.2.0/dbhome_2/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.
TESDB1 =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = primary_server_name)(PORT = 1522))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = TESDB1)
LISTENER_TESDB1 =
(ADDRESS = (PROTOCOL = TCP)(HOST = primary_server_name)(PORT = 1522))
And this listener.ora
# listener.ora Network Configuration File: /app/oracle/product/11.2.0/dbhome_2/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
(ADDRESS = (PROTOCOL = TCP)(HOST = primary_server_name)(PORT = 1522))
ADR_BASE_LISTENER = /app/oracle
So it seems it didn't update the network config. It has no knowledge of my standby TESDB1DR
I presume I can copy listener.ora and tnsnames.ora as configured in 11.2.0.1...
From 11.2.0.1 to 11.2.0.2 I don't think about major changes in these files... am I correct?
Thanks for your time.
Gianluca -
Hi Group,
I have a doubt.
When configure dataguard (10g, 11g), while archive received from the primary are applied the standby database also generates archives?No it just applies the archive from the primary. The only time it would generate is when you switch it to primary.
Remember the standby is in Read-only mode. (I assume from how the question was asked).
Does this answer your question? -
Hi,
I'm, using oracle 10.2.0.4 on Windows 2003,
I have dataguard setup, i have one doubt related to dblink in dataguard.
If i create a DB link in prod DB , can the same will be reflected in standby, as standby database is in mount state will it be create there,
also, the DMLs related to DML will reflect in standby,
Please clear my doubt, as i have to implement it in prod env.
Thanks
Edited by: user10745179 on Nov 5, 2012 11:31 AMHi;
I suggest please also review Dblink on Physical standby - ORA-16000 [ID 1296288.1] and also referance part
PS:For future issue you can use Forum Home » High Availability » DATA GUARD which is Dataguard dedicated forum site.
Regard
Helios -
Dataguard setup using hot backup files
Hello,
I am planning to setup dataguard using Hot backup (Not RMAN) files from the primary instance. I have a few doubt as, How shall I recover the Standby database using the archive files generated while taking hot backup of primary? Shall I directly execute the "alter database recover managed standby database" command? Will this command take care of the archives generated durring hot backup also?
Appreciate any help on the above.
DB Version:10.2.0.4
Regards.Guys by using below procedure you can rebuild your data gurad by using manual hot backup.
1) On the primary database, defer the archival of redo data .
ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=DEFER;
2)
put primary database in backup mode
copy all the datafiles from primary database to Standby database (you can copy to other location in primary server and tar&zip it and send it to stand by and unzip and untar there)
Once you copy the datafiles to another location on primary server,you can use below command for tar and zip
go to the copied datafiles location and issue below command
tar cvf - .|gzip -c > /dump/backup/drdb_backup.tar.gz
put primary database in end backup.
3) create stabdby controlfile by using below command and send it to standby server
alter database create standby controlfile as '/dump/drbackup/2standby.ctl'
4) copy all generated archive logs (from the time of database begin abckup) from primary database server to standby database log_archive_dest location.
5) on standby database once we placed all datafiles and controlfiles in place use below commands
export ORACLE_SID=standbydb
SQL> starup nomount;
SQL> alter database mount standby database;
SQL> recover standby database;
--AUTO
SQL> alter database open read only;
SQL> shut immediate
SQL> startup nomount;
SQL> alter database mount standby database;
SQL> alter database open read only;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
6) On the primary database, issue the following statement to reenable archiving to the physical standby database:
SQL> ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=ENABLE;
Thanks & Regards,
Satish Kumar Sadhu.
Edited by: Satish Kumar Sadhu on Apr 10, 2013 11:05 PM -
Fal_srver and fal_client doubt
Hi friends,
I have doubt on this parameter FAL_SERVER and Fal_client.
1.In oracle 11g FAL_CLIENT initialization no more required. then what about FAL_SERVER parameter ?
2.Is it mandatory to initialize the parameters during data guard configuration FAL_SERVER and FAL_CLIENT ?
3.if not mandatory then how automatic gap resolution done in case of dataguard ?
4.what is the role of archiver process in dataguard gap resolution ?
Thanks & Regards
AryaHi,
1.In oracle 11g FAL_CLIENT initialization no more required. then what about FAL_SERVER parameter ?
Yes, after 11g version FAL_CLIENT is no more required. FAL_SERVER parameter is require for data guard configuration.
2.Is it mandatory to initialize the parameters during data guard configuration FAL_SERVER and FAL_CLIENT ?
FAL_SERVER paramater is only for mandatory standby database. because, RFS using FAL_SERVER parameter for request redo changes.
FAL_SERVER is primary database.
3.if not mandatory then how automatic gap resolution done in case of dataguard ?
It is mandatory. When Automatic Gap Resolution is using standby database, RFS process using FAL_SERVER parameter for request
redo from primary for resolution redo gap.
4.what is the role of archiver process in dataguard gap resolution ?
When occur redo gap. Standby send request to primary via RFS, requested archive log sequence#.
NLS send info to ARCH process, and ARCH process connecting to standby RFS and sending requested archived log.
and MRP apply received archived logs.
Regards
Mahir M. Quluzade
http://www.mahir-quluzade.com
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