Error in DR alert log:-

FAL[client]: Failed to request gap sequence
GAP – thread 2 sequence 9432-9473
DBID 2085418592 branch 924361120
FAL[client]: All defined FAL servers have been attempted.
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Check that the CONTROL_FILE_RECORD_KEEP_TIME initialization
parameter is defined to a value that’s sufficiently large
enough to maintain adequate log switch information to resolve
archivelog gaps.
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Now in Primary,do the following steps to restore missing archive log

export ORACLE_SID=INSTANCE_NAME

rman target / catalog rcat/***@RCAT

run {
 allocate channel 'dev_00' type 'sbt_tape' parms 'SBT_LIBRARY=/opt/omni/lib/libob2oracle8_64bit.so,ENV=(OB2BARTYPE=Oracle8,OB2APPNAME=OCRMPD1,OB2BARLIST=CDV-PRD-DB-OCRMPD1_MENSUAL)';
 allocate channel 'dev_01' type 'sbt_tape' parms 'SBT_LIBRARY=/opt/omni/lib/libob2oracle8_64bit.so,ENV=(OB2BARTYPE=Oracle8,OB2APPNAME=OCRMPD1,OB2BARLIST=CDV-PRD-DB-OCRMPD1_MENSUAL)';
 allocate channel 'dev_02' type 'sbt_tape' parms 'SBT_LIBRARY=/opt/omni/lib/libob2oracle8_64bit.so,ENV=(OB2BARTYPE=Oracle8,OB2APPNAME=OCRMPD1,OB2BARLIST=CDV-PRD-DB-OCRMPD1_MENSUAL)';
 set archivelog destination to '/NFSPREPROD/NEW';
 RESTORE ARCHIVELOG FROM sequence 20453 thread 1;

RESTORE ARCHIVELOG FROM sequence 9432 thread 2;
 }