This post starts from one environment that you already enrolled in the database at ZDLRA. I already wrote about how to do that, you can check here in my previous post<\/a>. This is the first post about real-time redo, here you will see how to configure and verify it is working.<\/p>\n <\/p>\n The way that I configure real-time redo for database it is a little different than what is in the official docs. I added some pre-checks and another order for some steps, but the result is the same. If you want to check the official steps you can check at Zero Data Loss Recovery Appliance Protected Database Configuration Guide<\/a> or at Zero Data Loss Recovery Appliance Administrator’s Guide<\/a>.<\/p>\n Just contextualization of environment:<\/p>\n The first step that I do is verify the current configuration. Mainly the preexistence of wallet:<\/p>\n The most import here is the credential name (zdlras1-scan:1521\/zdlras1:CAT_ZDLRA<\/strong> in this case) because it needs to be the same name for the database file that points to RA_WALLET. The config file is for each database\/instance and has the name ra<DBNAME>.ora<\/strong> (it was already configured by the previous post pointed before).<\/p>\n After that, I check if the sqlnet.ora and tnsnames.ora have the information for wallet and TNS entry respectively:<\/p>\n After check outside of the database config, it is important to check some database requirements. The most import is verifying if REMOTE_LOGIN_PASSWORDFILE it is set as \u201cexclusive\u201d or \u201cshared\u201d:<\/p>\n Other parameters to verify are log_archive_config and db_unique_name. They are important to verify the current configuration in cases of databases using DG as an example.<\/p>\n After these pre-checks, we can start the configuration. Here I set everything at spfile to, after configuring everything, bounce the database and start with everything up and running.<\/p>\n It is the parameter that defines the user that the database utilizes to send the redo to another database. This user needs to exist in both databases (for DG), and because of that needs to exist in ZDLRA. When using ZDLRA and real-time redo it needs to be the same<\/strong> as VPC inside the database. So, the same VPC user needs to exists in database side and set for this parameter:<\/p>\n As you can see the user CAT_ZDLRA was created inside of the database. The user needs to have at least the grant SYSOPER to work properly.<\/p>\n This parameter works the same for DG environments, and since ZDLRA real-time redo it is a remote destination for archive, we do the same. Here, we set this specifying the database unique name for ZDLRA here (zdlras1 in my current environment):<\/p>\n If you already have DG configured, you need to just add the entry for ZDLRA database here in the parameter.<\/p>\n The secrets are:<\/p>\n All the others are the normal parameters for DG config and you can check at LOG_ARCHIVE_DEST_n Parameter Attributes<\/a>.<\/p>\n As I told before, the ASYNC NOAFFIRM are controversial because if you look it was defined as ASYNC, and it is the same in the ZDLRA docs. You can read here at \u201cProtection of Ongoing Transactions<\/a>\u201d (or at \u201cHow Real-Time Redo Transport Works<\/a>\u201d):<\/p>\n \u201cRedo data from the protected database is written asynchronously to the Recovery Appliance as it is generated. Load on production database servers is minimized because redo data is shipped directly from the memory to the Recovery Appliance without the involvement of disk I\/O\u201d<\/em><\/p>\n \u201cTo avoid degrading the performance of the protected database, protected databases transfer redo asynchronously to the Recovery Appliance. If a protected database is lost, zero to subsecond data loss is expected in most cases.<\/strong>\u201d<\/em><\/p>\n![\"\"](\"http:\/\/www.fernandosimon.com\/blog\/wp-content\/uploads\/2019\/10\/Real-Time-Redo-Transport.png\"){kind=spacer}
<\/a><\/p>\nPre-Check<\/h2>\n
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Check Configuration<\/h3>\n
[oracle@orcloel7 ~]$ mkstore -wrl \/u01\/app\/oracle\/product\/19.3.0.0\/dbhome_1\/dbs\/ra_wallet -listCredential\r\nOracle Secret Store Tool Release 19.0.0.0.0 - Production\r\nVersion 19.3.0.0.0\r\nCopyright (c) 2004, 2019, Oracle and\/or its affiliates. All rights reserved.\r\n\r\nList credential (index: connect_string username)\r\n1: zdlras1-scan:1521\/zdlras1:CAT_ZDLRA cat_zdlra\r\n[oracle@orcloel7 ~]$\r\n[oracle@orcloel7 ~]$ cat $ORACLE_HOME\/dbs\/raORCL19.ora\r\nRA_WALLET='LOCATION=file:\/u01\/app\/oracle\/product\/19.3.0.0\/dbhome_1\/dbs\/ra_wallet CREDENTIAL_ALIAS=zdlras1-scan:1521\/zdlras1:CAT_ZDLRA'\r\n[oracle@orcloel7 ~]$<\/pre>\n
[oracle@orcloel7 ~]$ cat $ORACLE_HOME\/network\/admin\/sqlnet.ora\r\nNAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)\r\n\r\nSQLNET.WALLET_OVERRIDE = true\r\n\r\nWALLET_LOCATION =\r\n(\r\n SOURCE =\r\n (METHOD = FILE)\r\n (METHOD_DATA =\r\n (DIRECTORY = \/u01\/app\/oracle\/product\/19.3.0.0\/dbhome_1\/dbs\/ra_wallet)\r\n )\r\n)\r\n[oracle@orcloel7 ~]$\r\n[oracle@orcloel7 ~]$ tnsping zdlras1\r\n\r\nTNS Ping Utility for Linux: Version 19.0.0.0.0 - Production on 01-OCT-2019 23:30:36\r\n\r\nCopyright (c) 1997, 2019, Oracle. All rights reserved.\r\n\r\nUsed parameter files:\r\n\/u01\/app\/oracle\/product\/19.3.0.0\/dbhome_1\/network\/admin\/sqlnet.ora\r\n\r\n\r\nUsed TNSNAMES adapter to resolve the alias\r\nAttempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = zdlras1-scan)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = zdlras1)))\r\nOK (0 msec)\r\n[oracle@orcloel7 ~]$\r\n<\/pre>\n
Check Database Configuration<\/h3>\n
[oracle@orcloel7 ~]$ sqlplus \/ as sysdba\r\n\r\nSQL*Plus: Release 19.0.0.0.0 - Production on Tue Oct 1 23:32:09 2019\r\nVersion 19.3.0.0.0\r\n\r\nCopyright (c) 1982, 2019, Oracle. All rights reserved.\r\n\r\n\r\nConnected to:\r\nOracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production\r\nVersion 19.3.0.0.0\r\n\r\nSQL>\r\nSQL> show parameter REMOTE_LOGIN_PASSWORDFILE;\r\n\r\nNAME TYPE VALUE\r\n------------------------------------ ----------- ------------------------------\r\nremote_login_passwordfile string EXCLUSIVE\r\nSQL>\r\nSQL><\/pre>\n
Configuring Real-Time Redo<\/h2>\n
REDO_TRANSPORT_USER<\/h3>\n
SQL> show parameter redo_transport_user;\r\n\r\nNAME TYPE VALUE\r\n------------------------------------ ----------- ------------------------------\r\nredo_transport_user string\r\nSQL>\r\nSQL> alter system set redo_transport_user='CAT_ZDLRA' scope = spfile SID='*';\r\n\r\nSystem altered.\r\n\r\nSQL>\r\nSQL> create user cat_zdlra identified by s3nhazdlra;\r\n\r\nUser created.\r\n\r\nSQL> grant sysoper to cat_zdlra;\r\n\r\nGrant succeeded.\r\n\r\nSQL><\/pre>\n
LOG_ARCHIVE_CONFIG<\/h3>\n
SQL> show parameter log_archive_config;\r\n\r\nNAME TYPE VALUE\r\n------------------------------------ ----------- ------------------------------\r\nlog_archive_config string\r\nSQL>\r\nSQL> show parameter db_unique_name;\r\n\r\nNAME TYPE VALUE\r\n------------------------------------ ----------- ------------------------------\r\ndb_unique_name string ORCL19\r\nSQL>\r\nSQL> ALTER SYSTEM SET log_archive_config='DG_CONFIG=(orcl19,zdlras1)' SCOPE=SPFILE SID='*';\r\n\r\nSystem altered.\r\n\r\nSQL>\r\n<\/pre>\n
LOG_ARCHIVE_DEST_n<\/h3>\n
SQL> ALTER SYSTEM SET log_archive_dest_2='SERVICE=\"zdlras1-scan:1521\/zdlras1:CAT_ZDLRA\" ASYNC NOAFFIRM delay=0 optional compression=disable max_failure=1 max_connections=1 reopen=10 DB_UNIQUE_NAME=zdlras1 net_timeout=8 group=1 priority=1 VALID_FOR=(ONLINE_LOGFILE,ALL_ROLES)' scope = spfile sid = '*';\r\n\r\nSystem altered.\r\n\r\nSQL>\r\nSQL> alter system set log_archive_dest_state_2=DEFER scope = spfile sid = '*';\r\n\r\nSystem altered.\r\n\r\nSQL><\/pre>\n
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