Update monitoring to include average time per compaction and stall

Summary:
The new columns are msComp and msStall that provide average time per compaction and stall for that level in milliseconds.
Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count   msComp   msStall  Ln-stall Stall-cnt
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  0        8       15   1.5         2         0        30         0         0        30        0.0       0.0        15.5        0        0        0        0       16      112       0.2       1.3      7568
  1        8       16   1.6         1        26        26        15        11        16        3.5      17.6        18.1        8        6       13        7        3      362       0.0       0.0         0
  2        1        2   0.0         0         0         2         0         0         2        0.0       0.0        18.4        0        0        0        0        1       50       0.0       0.0         0

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15345

db/db_impl.cc

@@ -3545,8 +3545,8 @@ bool DBImpl::GetProperty(const Slice& property, std::string* value) {
     // Pardon the long line but I think it is easier to read this way.
     snprintf(buf, sizeof(buf),
              "                               Compactions\n"
-             "Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count  Ln-stall Stall-cnt\n"
-             "--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\n"
+             "Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count   msComp   msStall  Ln-stall Stall-cnt\n"
+             "------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------\n"
              );
     value->append(buf);
     for (int level = 0; level < current->NumberLevels(); level++) {
@@ -3566,9 +3566,21 @@ bool DBImpl::GetProperty(const Slice& property, std::string* value) {
         total_bytes_read += bytes_read;
         total_bytes_written += stats_[level].bytes_written;
 
+        uint64_t stalls = level == 0 ?
+            (stall_level0_slowdown_count_ +
+             stall_level0_num_files_count_ +
+             stall_memtable_compaction_count_) :
+            stall_leveln_slowdown_count_[level];
+
+        double stall_us = level == 0 ?
+            (stall_level0_slowdown_ +
+             stall_level0_num_files_ +
+             stall_memtable_compaction_) :
+            stall_leveln_slowdown_[level];
+
         snprintf(
             buf, sizeof(buf),
-            "%3d %8d %8.0f %5.1f %9.0f %9.0f %9.0f %9.0f %9.0f %9.0f %10.1f %9.1f %11.1f %8d %8d %8d %8d %8d %9.1f %9lu\n",
+            "%3d %8d %8.0f %5.1f %9.0f %9.0f %9.0f %9.0f %9.0f %9.0f %10.1f %9.1f %11.1f %8d %8d %8d %8d %8d %8d %9.1f %9.1f %9lu\n",
             level,
             files,
             current->NumLevelBytes(level) / 1048576.0,
@@ -3590,8 +3602,13 @@ bool DBImpl::GetProperty(const Slice& property, std::string* value) {
             stats_[level].files_out_levelnp1,
             stats_[level].files_out_levelnp1 - stats_[level].files_in_levelnp1,
             stats_[level].count,
-            stall_leveln_slowdown_[level] / 1000000.0,
-            (unsigned long) stall_leveln_slowdown_count_[level]);
+            (int) ((double) stats_[level].micros /
+                   1000.0 /
+                   (stats_[level].count + 1)),
+            (double) stall_us / 1000.0 / (stalls + 1),
+            stall_us / 1000000.0,
+            (unsigned long) stalls);
+
         total_slowdown += stall_leveln_slowdown_[level];
         total_slowdown_count += stall_leveln_slowdown_count_[level];
         value->append(buf);