Summary:
After secondary instance replays the logs from primary, certain files become
obsolete. The secondary should find these files, evict their table readers from
table cache and close them. If this is not done, the secondary will hold on to
these files and prevent their space from being freed.
Test plan (devserver):
```
$./db_secondary_test --gtest_filter=DBSecondaryTest.SecondaryCloseFiles
$make check
$./db_stress -ops_per_thread=100000 -enable_secondary=true -threads=32 -secondary_catch_up_one_in=10000 -clear_column_family_one_in=1000 -reopen=100
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6114
Differential Revision: D18769998
Pulled By: riversand963
fbshipit-source-id: 5d1f151567247196164e1b79d8402fa2045b9120
Summary:
`DBImplSecondary` calls `CheckConsistency()` during open. In the past, `DBImplSecondary` did not override this function thus `DBImpl::CheckConsistency()` is called.
The following can happen. The secondary instance is performing consistency check which calls `GetFileSize(file_path)` but the file at `file_path` is deleted by the primary instance. `DBImpl::CheckConsistency` does not account for this and fails the consistency check. This is undesirable. The solution is that, we call `DBImpl::CheckConsistency()` first. If it passes, then we are good. If not, we give it a second chance and handles the case of file(s) being deleted.
Test plan (on dev server):
```
$make clean && make -j20 all
$./db_secondary_test
```
All other existing unit tests must pass as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5469
Differential Revision: D15861845
Pulled By: riversand963
fbshipit-source-id: 507d72392508caed3cd003bb2e2aa43f993dd597
