MB-35331: Increment flusher_todo for set_vbucket_state

Ensure wait_for_flusher_to_settle waits for a set_vbucket_state
by increasing the flusher_todo, which will be cleared once
the flusher has committed its batch.

Commit also includes further debug for warmup_mb21769 test as
that still fails, even with the flusher_todo increment

Change-Id: Ib78ecc0f02da95a6aee3c9031bf445c7a11d365a
Reviewed-on: http://review.couchbase.org/113616
Tested-by: Build Bot <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: jimwwalker

engines/ep/src/ep_bucket.cc

@@ -466,7 +466,10 @@ std::pair<bool, size_t> EPBucket::flushVBucket(Vbid vbid) {
                     // no 'real' items in the checkpoint.
                     mustCheckpointVBState = true;
 
-                    // Update queuing stats how this item has logically been
+                    // There is at least a commit to be done, so increase todo
+                    ++stats.flusher_todo;
+
+                    // Update queuing stats now this item has logically been
                     // processed.
                     --stats.diskQueueSize;
                     vb->doStatsForFlushing(*item, item->size());

engines/ep/tests/ep_testsuite_basic.cc

@@ -1870,11 +1870,23 @@ static enum test_result warmup_mb21769(EngineIface* h) {
                 get_ull_stat(h, snap_end.c_str(), vb_group_key.c_str()),
                 std::string("snap_end incorrect vb:" + std::to_string(vb))
                         .c_str());
-        checkeq(failover_entry0[vb],
-                get_ull_stat(h, fail0.c_str(), failovers_key.c_str()),
-                std::string("failover table entry 0 is incorrect vb:" +
-                            std::to_string(vb))
-                        .c_str());
+        auto failoverTable = get_all_stats(h, failovers_key.c_str());
+        if (failoverTable[fail0] != std::to_string(failover_entry0[vb])) {
+            std::cerr << "failover table entry 0 is incorrect for vb:" << vb
+                      << " expected:" << failover_entry0[vb]
+                      << " got:" << failoverTable[fail0]
+                      << " dumping failover table\n";
+            for (const auto& stat : failoverTable) {
+                std::cerr << stat.first << ":" << stat.second << std::endl;
+            }
+            std::string detail = "vbucket-details " + std::to_string(vb);
+            auto details = get_all_stats(h, detail.c_str());
+            std::cerr << detail << std::endl;
+            for (const auto& stat : details) {
+                std::cerr << stat.first << ":" << stat.second << std::endl;
+            }
+            return FAIL;
+        }
     }
 
     return SUCCESS;