copy queue length increase for some Exchange DB in DR Server

Hi All

 We are  enabled  the  DAG in our Exchange 2010 Setup which includes 2 nos of mail box server, Primary and DR.  I observed  in our DR server  some database Copy Queue length was increased  to some 500 to 1000.  we have some  10 DBs in our exchange setup only 2 DBs are showing this  issue. I  checked with Test-ReplicationHealth  cmd  with my DR Server it shows  failed error on DBLogCopyKeepingup.

any body please helpme to resolve the issue, much much appreciated.

Best Regards

Jaga

Jags