Make a StatsApi object instance-local

Summary: If we spin up multiple mcrouter instances in a process we want to have separate stats collection for each. This removes the global singleton.

Differential Revision: D69613438

fbshipit-source-id: 7defc5714a4cf50a421a43053f15ad1cab1ebda3

Author: Anton Likhtarov

third-party/mcrouter/src/mcrouter/CarbonRouterInstanceBase.cpp

@@ -76,11 +76,8 @@ CarbonRouterInstanceBase::CarbonRouterInstanceBase(McrouterOptions inputOptions)
       configApi_(createConfigApi(opts_)),
       rtVarsData_(std::make_shared<ObservableRuntimeVars>()),
       leaseTokenMap_(globalFunctionScheduler.try_get()),
-      statsUpdateFunctionHandle_(statsUpdateFunctionName(opts_.router_name)) {
-  if (gStatsApiInitHook) {
-    gStatsApiInitHook(*this);
-  }
-
+      statsUpdateFunctionHandle_(statsUpdateFunctionName(opts_.router_name)),
+      statsApi_(gMakeStatsApiHook ? gMakeStatsApiHook(*this) : nullptr) {
   if (auto statsLogger = statsLogWriter()) {
     if (opts_.stats_async_queue_length) {
       statsLogger->increaseMaxQueueSize(opts_.stats_async_queue_length);

third-party/mcrouter/src/mcrouter/CarbonRouterInstanceBase.h

@@ -254,6 +254,10 @@ class CarbonRouterInstanceBase {
     axonProxyClientFactory_ = std::move(clientFactory);
   }
 
+  StatsApi* statsApi() {
+    return statsApi_.get();
+  }
+
   /**
    * Runtime features that can be enabled from runtime_features block
    * in routing config
@@ -352,6 +356,8 @@ class CarbonRouterInstanceBase {
   std::shared_ptr<void> metadata_;
 
   std::shared_ptr<void> axonProxyClientFactory_;
+
+  std::unique_ptr<StatsApi> statsApi_;
 };
 
 } // namespace mcrouter

third-party/mcrouter/src/mcrouter/ProxyBase-inl.h

@@ -32,7 +32,7 @@ ProxyBase::ProxyBase(
           std::make_unique<folly::fibers::EventBaseLoopController>(),
           getFiberManagerOptions(router_.opts())),
       asyncLog_(router_.opts()),
-      stats_(router_.getStatsEnabledPools()),
+      stats_(router_.getStatsEnabledPools(), router_.statsApi()),
       flushCallback_(*this),
       destinationMap_(std::make_unique<ProxyDestinationMap>(this)) {
   // Setup a full random seed sequence

third-party/mcrouter/src/mcrouter/ProxyStats.cpp

@@ -11,7 +11,10 @@ namespace facebook {
 namespace memcache {
 namespace mcrouter {
 
-ProxyStats::ProxyStats(const std::vector<std::string>& statsEnabledPools) {
+ProxyStats::ProxyStats(
+    const std::vector<std::string>& statsEnabledPools,
+    StatsApi* statsApi)
+    : statsApi_(statsApi) {
   init_stats(stats_);
   poolStats_.reserve(statsEnabledPools.size());
   for (const auto& curPoolName : statsEnabledPools) {

third-party/mcrouter/src/mcrouter/ProxyStats.h

@@ -21,7 +21,9 @@ namespace mcrouter {
 
 class ProxyStats {
  public:
-  explicit ProxyStats(const std::vector<std::string>& statsEnabledPools);
+  explicit ProxyStats(
+      const std::vector<std::string>& statsEnabledPools,
+      StatsApi* statsApi);
 
   /**
    * Aggregate proxy stat with the given index.
@@ -107,7 +109,7 @@ class ProxyStats {
    * @param amount  Amount to increment the stat
    */
   void increment(stat_name_t stat, int64_t amount = 1) {
-    stat_incr(stats_, stat, amount);
+    stat_incr(stats_, statsApi_, stat, amount);
   }
 
   /**
@@ -127,7 +129,7 @@ class ProxyStats {
    * @param amount  Amount to increment the stat
    */
   void incrementSafe(stat_name_t stat, int64_t amount = 1) {
-    stat_fetch_add(stats_, stat, amount);
+    stat_fetch_add(stats_, statsApi_, stat, amount);
   }
 
   /**
@@ -147,7 +149,7 @@ class ProxyStats {
    * @param newValue  New value of the stat
    */
   void setValue(stat_name_t stat, uint64_t newValue) {
-    stat_set(stats_, stat, newValue);
+    stat_set(stats_, statsApi_, stat, newValue);
   }
 
   uint64_t getValue(stat_name_t stat) {
@@ -190,6 +192,7 @@ class ProxyStats {
   stat_t stats_[num_stats]{};
   // vector of the PoolStats
   std::vector<PoolStats> poolStats_;
+  StatsApi* statsApi_{nullptr};
 
   ExponentialSmoothData<64> durationUs_;
   // Duration microseconds, broken down by get-like request type

third-party/mcrouter/src/mcrouter/TargetHooks.h

@@ -9,12 +9,17 @@
 
 #include <folly/Portability.h>
 #include <folly/executors/IOThreadPoolExecutor.h>
-#include "mcrouter/options.h"
 
 namespace facebook {
 namespace memcache {
+
+class McrouterOptions;
+
 namespace mcrouter {
 
+class CarbonRouterInstanceBase;
+class StatsApi;
+
 /**
  * If linked, initializes and reports utilization to RIM.
  */
@@ -33,19 +38,12 @@ FOLLY_ATTR_WEAK void gAxonInitHook(
     CarbonRouterInstanceBase& router,
     std::shared_ptr<folly::IOThreadPoolExecutorBase> ioThreadPool);
 
-class StatsApi;
-
-/**
- * If linked, returns a reference to a StatsApi implementation allowing
- * custom stats handling.
- */
-FOLLY_ATTR_WEAK StatsApi& gStatsApiHook();
-
 /**
  * If linked, will be called once on router initialization with the intent
  * to initialize the custom StatsApi implementation.
  */
-FOLLY_ATTR_WEAK void gStatsApiInitHook(const CarbonRouterInstanceBase& router);
+FOLLY_ATTR_WEAK std::unique_ptr<StatsApi> gMakeStatsApiHook(
+    const CarbonRouterInstanceBase& router);
 
 } // namespace mcrouter
 } // namespace memcache