add interface to flush dc_lsn (eBay#863)

flush_durable_commit_lsn is used to persist the dc_lsn of a repl_dev. for raft_repl_dev, all the logs between cp_lsn and dc lsn will be  recommitted again in log replay when restart.

Author: JacksonYao287

conanfile.py

@@ -9,7 +9,7 @@
 
 class HomestoreConan(ConanFile):
     name = "homestore"
-    version = "7.3.3"
+    version = "7.4.1"
 
     homepage = "https://github.com/eBay/Homestore"
     description = "HomeStore Storage Engine"

src/include/homestore/replication/repl_dev.h

@@ -624,6 +624,8 @@ class ReplDev {
 
     virtual void reset_latch_lsn() { return; }
 
+    virtual void flush_durable_commit_lsn() {}
+
     virtual shared< ReplDevListener > get_listener() { return m_listener; }
 
     // we have no shutdown for repl_dev, since shutdown repl_dev is done by repl_service

src/lib/replication/repl_dev/raft_repl_dev.h

@@ -420,7 +420,7 @@ class RaftReplDev : public ReplDev,
     /**
      * Flush the durable commit LSN to the superblock
      */
-    void flush_durable_commit_lsn();
+    void flush_durable_commit_lsn() override;
 
     /**
      * Monitor the replace_member replication status, if the new member is fully synced up and ready to take over,