Four new persistence fields in INFO. A few renamed.

The 'persistence' section of INFO output now contains additional four
fields related to RDB and AOF persistence:

 rdb_last_bgsave_time_sec       Duration of latest BGSAVE in sec.
 rdb_current_bgsave_time_sec    Duration of current BGSAVE in sec.
 aof_last_rewrite_time_sec      Duration of latest AOF rewrite in sec.
 aof_current_rewrite_time_sec   Duration of current AOF rewrite in sec.

The 'current' fields are set to -1 if a BGSAVE / AOF rewrite is not in
progress. The 'last' fileds are set to -1 if no previous BGSAVE / AOF
rewrites were performed.

Additionally a few fields in the persistence section were renamed for
consistency:

 changes_since_last_save -> rdb_changes_since_last_save
 bgsave_in_progress -> rdb_bgsave_in_progress
 last_save_time -> rdb_last_save_time
 last_bgsave_status -> rdb_last_bgsave_status
 bgrewriteaof_in_progress -> aof_rewrite_in_progress
 bgrewriteaof_scheduled -> aof_rewrite_scheduled

After the renaming, fields in the persistence section start with rdb_ or
aof_ prefix depending on the persistence method they describe.
The field 'loading' and related fields are not prefixed because they are
unique for both the persistence methods.

src/aof.c

@@ -154,6 +154,7 @@ void stopAppendOnly(void) {
         aofRewriteBufferReset();
         aofRemoveTempFile(server.aof_child_pid);
         server.aof_child_pid = -1;
+        server.aof_rewrite_time_start = -1;
     }
 }
 
@@ -941,6 +942,7 @@ int rewriteAppendOnlyFileBackground(void) {
         redisLog(REDIS_NOTICE,
             "Background append only file rewriting started by pid %d",childpid);
         server.aof_rewrite_scheduled = 0;
+        server.aof_rewrite_time_start = time(NULL);
         server.aof_child_pid = childpid;
         updateDictResizePolicy();
         /* We set appendseldb to -1 in order to force the next call to the
@@ -1113,6 +1115,8 @@ cleanup:
     aofRewriteBufferReset();
     aofRemoveTempFile(server.aof_child_pid);
     server.aof_child_pid = -1;
+    server.aof_rewrite_time_last = time(NULL)-server.aof_rewrite_time_start;
+    server.aof_rewrite_time_start = -1;
     /* Schedule a new rewrite if we are waiting for it to switch the AOF ON. */
     if (server.aof_state == REDIS_AOF_WAIT_REWRITE)
         server.aof_rewrite_scheduled = 1;

src/rdb.c

@@ -708,6 +708,7 @@ int rdbSaveBackground(char *filename) {
             return REDIS_ERR;
         }
         redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
+        server.rdb_save_time_start = time(NULL);
         server.rdb_child_pid = childpid;
         updateDictResizePolicy();
         return REDIS_OK;
@@ -1152,6 +1153,8 @@ void backgroundSaveDoneHandler(int exitcode, int bysignal) {
         server.lastbgsave_status = REDIS_ERR;
     }
     server.rdb_child_pid = -1;
+    server.rdb_save_time_last = time(NULL)-server.rdb_save_time_start;
+    server.rdb_save_time_start = -1;
     /* Possibly there are slaves waiting for a BGSAVE in order to be served
      * (the first stage of SYNC is a bulk transfer of dump.rdb) */
     updateSlavesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);

src/redis.c

@@ -1111,6 +1111,8 @@ void initServerConfig() {
     server.aof_rewrite_base_size = 0;
     server.aof_rewrite_scheduled = 0;
     server.aof_last_fsync = time(NULL);
+    server.aof_rewrite_time_last = -1;
+    server.aof_rewrite_time_start = -1;
     server.aof_delayed_fsync = 0;
     server.aof_fd = -1;
     server.aof_selected_db = -1; /* Make sure the first time will not match */
@@ -1304,6 +1306,8 @@ void initServer() {
     aofRewriteBufferReset();
     server.aof_buf = sdsempty();
     server.lastsave = time(NULL);
+    server.rdb_save_time_last = -1;
+    server.rdb_save_time_start = -1;
     server.dirty = 0;
     server.stat_numcommands = 0;
     server.stat_numconnections = 0;
@@ -1900,21 +1904,31 @@ sds genRedisInfoString(char *section) {
         info = sdscatprintf(info,
             "# Persistence\r\n"
             "loading:%d\r\n"
+            "rdb_changes_since_last_save:%lld\r\n"
+            "rdb_bgsave_in_progress:%d\r\n"
+            "rdb_last_save_time:%ld\r\n"
+            "rdb_last_bgsave_status:%s\r\n"
+            "rdb_last_bgsave_time_sec:%ld\r\n"
+            "rdb_current_bgsave_time_sec:%ld\r\n"
             "aof_enabled:%d\r\n"
-            "changes_since_last_save:%lld\r\n"
-            "bgsave_in_progress:%d\r\n"
-            "last_save_time:%ld\r\n"
-            "last_bgsave_status:%s\r\n"
-            "bgrewriteaof_in_progress:%d\r\n"
-            "bgrewriteaof_scheduled:%d\r\n",
+            "aof_rewrite_in_progress:%d\r\n"
+            "aof_rewrite_scheduled:%d\r\n"
+            "aof_last_rewrite_time_sec:%ld\r\n"
+            "aof_current_rewrite_time_sec:%ld\r\n",
             server.loading,
-            server.aof_state != REDIS_AOF_OFF,
             server.dirty,
             server.rdb_child_pid != -1,
             server.lastsave,
             server.lastbgsave_status == REDIS_OK ? "ok" : "err",
+            server.rdb_save_time_last,
+            (server.rdb_child_pid == -1) ?
+                -1 : time(NULL)-server.rdb_save_time_start,
+            server.aof_state != REDIS_AOF_OFF,
             server.aof_child_pid != -1,
-            server.aof_rewrite_scheduled);
+            server.aof_rewrite_scheduled,
+            server.aof_rewrite_time_last,
+            (server.aof_child_pid == -1) ?
+                -1 : time(NULL)-server.aof_rewrite_time_start);
 
         if (server.aof_state != REDIS_AOF_OFF) {
             info = sdscatprintf(info,

src/redis.h

@@ -640,6 +640,8 @@ struct redisServer {
     int aof_selected_db; /* Currently selected DB in AOF */
     time_t aof_flush_postponed_start; /* UNIX time of postponed AOF flush */
     time_t aof_last_fsync;            /* UNIX time of last fsync() */
+    time_t aof_rewrite_time_last;   /* Time used by last AOF rewrite run. */
+    time_t aof_rewrite_time_start;  /* Current AOF rewrite start time. */
     unsigned long aof_delayed_fsync;  /* delayed AOF fsync() counter */
     /* RDB persistence */
     long long dirty;                /* Changes to DB from the last save */
@@ -651,6 +653,8 @@ struct redisServer {
     int rdb_compression;            /* Use compression in RDB? */
     int rdb_checksum;               /* Use RDB checksum? */
     time_t lastsave;                /* Unix time of last save succeeede */
+    time_t rdb_save_time_last;      /* Time used by last RDB save run. */
+    time_t rdb_save_time_start;     /* Current RDB save start time. */
     int lastbgsave_status;          /* REDIS_OK or REDIS_ERR */
     int stop_writes_on_bgsave_err;  /* Don't allow writes if can't BGSAVE */
     /* Propagation of commands in AOF / replication */