mongodb - mongo java driver returning stale data from primary -

i using mongo version 2.4.5 , mongo-java-driver version 2.12.4. have primary node , replica.

now run code following:

save 1 - inserts new document default write concern  ...waits time  read 1 - reads document read preference primary  ...modifies  save 2 - save modified doc default write concern  read 2 - reads saved doc read preference primary 

in last read operation, done after save, see stale data returned in cases(that modifications not reflecting). however, in cases modifications reflect.

question - if writing mongo default write concern(which acknowledged) , reading preference primary, isn't consistency guaranteed?

more details:

1. application connecting replica set 1 primary , 1 secondary host.

2. i tried overriding default write concern following: acknowledged, journaled, relpica_acknowledged in cases, read preference primary. still issue observed.

   private dbcollection customers = mydb.getcollection("customers");

   writeresult wr = customers.save(customer,concern);

   if (wr.getn() > 0) {

   ans = true;

   } else ans = false;

   } catch (exception e) {

   ans = false;

   e.printstacktrace();

   }