Admin stats render histograms

envoy/stats/histogram.h

@@ -167,6 +167,14 @@ class ParentHistogram : public Histogram {
    * Returns the bucket summary representation.
    */
   virtual std::string bucketSummary() const PURE;
+
+  struct Bucket {
+    double value_{0};
+    uint64_t count_{0};
+  };
+
+  virtual std::vector<Bucket> detailedTotalBuckets(uint32_t max_buckets = 0) const PURE;
+  virtual std::vector<Bucket> detailedIntervalBuckets(uint32_t max_buckets = 0) const PURE;
 };
 
 using ParentHistogramSharedPtr = RefcountPtr<ParentHistogram>;

source/common/stats/histogram_impl.h

@@ -49,8 +49,6 @@ class HistogramStatisticsImpl final : public HistogramStatistics, NonCopyable {
       const histogram_t* histogram_ptr, Histogram::Unit unit = Histogram::Unit::Unspecified,
       ConstSupportedBuckets& supported_buckets = HistogramSettingsImpl::defaultBuckets());
 
-  static ConstSupportedBuckets& defaultSupportedBuckets();
-
   void refresh(const histogram_t* new_histogram_ptr);
 
   // HistogramStatistics

source/common/stats/thread_local_store.cc

@@ -958,6 +958,54 @@ std::string ParentHistogramImpl::bucketSummary() const {
   }
 }
 
+std::vector<Stats::ParentHistogram::Bucket>
+ParentHistogramImpl::detailedTotalBuckets(uint32_t max_buckets) const {
+  return detailedlBucketsHelper(max_buckets, *cumulative_histogram_);
+}
+
+std::vector<Stats::ParentHistogram::Bucket>
+ParentHistogramImpl::detailedIntervalBuckets(uint32_t max_buckets) const {
+  return detailedlBucketsHelper(max_buckets, *interval_histogram_);
+}
+
+std::vector<Stats::ParentHistogram::Bucket>
+ParentHistogramImpl::detailedlBucketsHelper(uint32_t max_buckets, const histogram_t& histogram) {
+  const uint32_t num_src_buckets = hist_num_buckets(&histogram);
+  if (max_buckets == 0) {
+    max_buckets = num_src_buckets;
+  }
+  const uint32_t num_buckets = std::min(max_buckets, num_src_buckets);
+  uint32_t num_src_buckets_per_bucket = 1;
+  uint32_t remainder = 0;
+  if (num_src_buckets > num_buckets) {
+    num_src_buckets_per_bucket = num_src_buckets / num_buckets;
+    remainder = num_src_buckets - num_buckets * num_src_buckets_per_bucket;
+    ASSERT(remainder < num_buckets);
+  }
+
+  std::vector<Stats::ParentHistogram::Bucket> buckets(num_buckets);
+  uint32_t src = 0;
+  for (uint32_t dest = 0; dest < num_buckets; ++dest) {
+    ParentHistogram::Bucket& bucket = buckets[dest];
+    uint32_t merges = num_src_buckets_per_bucket;
+    if (remainder > 0) {
+      ++merges;
+      --remainder;
+    }
+    for (uint32_t i = 0; i < merges; ++i, ++src) {
+      ASSERT(src < num_src_buckets);
+      double value;
+      uint64_t count;
+      /*int ret = */ hist_bucket_idx(&histogram, src, &value, &count);
+      bucket.count_ += count;
+      bucket.value_ += value;
+    }
+    bucket.value_ /= merges;
+  }
+  ASSERT(src == num_src_buckets);
+  return buckets;
+}
+
 void ParentHistogramImpl::addTlsHistogram(const TlsHistogramSharedPtr& hist_ptr) {
   Thread::LockGuard lock(merge_lock_);
   tls_histograms_.emplace_back(hist_ptr);

source/common/stats/thread_local_store.h

@@ -105,6 +105,8 @@ class ParentHistogramImpl : public MetricImpl<ParentHistogram> {
   }
   std::string quantileSummary() const override;
   std::string bucketSummary() const override;
+  std::vector<Bucket> detailedTotalBuckets(uint32_t max_buckets) const override;
+  std::vector<Bucket> detailedIntervalBuckets(uint32_t max_buckets) const override;
 
   // Stats::Metric
   SymbolTable& symbolTable() override;
@@ -121,6 +123,8 @@ class ParentHistogramImpl : public MetricImpl<ParentHistogram> {
 
 private:
   bool usedLockHeld() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(merge_lock_);
+  static std::vector<Stats::ParentHistogram::Bucket>
+  detailedlBucketsHelper(uint32_t max_buckets, const histogram_t& histogram);
 
   Histogram::Unit unit_;
   ThreadLocalStoreImpl& thread_local_store_;

source/server/admin/admin.cc

@@ -186,7 +186,8 @@ AdminImpl::AdminImpl(const std::string& profile_path, Server::Instance& server,
                       MAKE_ADMIN_HANDLER(server_info_handler_.handlerServerInfo), false, false),
           makeHandler("/ready", "print server state, return 200 if LIVE, otherwise return 503",
                       MAKE_ADMIN_HANDLER(server_info_handler_.handlerReady), false, false),
-          stats_handler_.statsHandler(false /* not active mode */),
+          stats_handler_.statsHandler("/stats", false /* not active mode */),
+          stats_handler_.statsHandler("/stats/html-active", true),
           stats_handler_.prometheusStatsHandler(),
           makeHandler("/stats/recentlookups", "Show recent stat-name lookups",
                       MAKE_ADMIN_HANDLER(stats_handler_.handlerStatsRecentLookups), false, false),

source/server/admin/admin_html.cc

@@ -12,7 +12,7 @@ namespace Server {
 Http::Code AdminImpl::handlerAdminHome(Http::ResponseHeaderMap& response_headers,
                                        Buffer::Instance& response, AdminStream&) {
   AdminHtmlUtil::renderHead(response_headers, response);
-  AdminHtmlUtil::renderTableBegin(response);
+  AdminHtmlUtil::renderTableBegin(response, "Command");
 
   // Prefix order is used during searching, but for printing do them in alpha order.
   OptRef<const Http::Utility::QueryParams> no_query_params;

source/server/admin/admin_html_util.cc

@@ -12,7 +12,7 @@ const char AdminHtmlTableBegin[] = R"(
   <table class='home-table'>
     <thead>
       <tr>
-        <th class='home-data'>Command</th>
+        <th class='home-data'>@NAME_COLUMN@</th>
         <th class='home-data'>Description</th>
       </tr>
     </thead>
@@ -58,6 +58,7 @@ class BuiltinResourceProvider : public AdminHtmlUtil::ResourceProvider {
     map_["admin_head_start.html"] = AdminHtmlStart;
     map_["admin.css"] = AdminCss;
     map_["active_stats.js"] = AdminActiveStatsJs;
+    map_["histograms.js"] = HistogramsJs;
     map_["active_params.html"] = AdminActiveParamsHtml;
   }
 
@@ -111,8 +112,8 @@ void AdminHtmlUtil::renderHead(Http::ResponseHeaderMap& response_headers,
   response.add("</head>\n<body>\n");
 }
 
-void AdminHtmlUtil::renderTableBegin(Buffer::Instance& response) {
-  response.add(AdminHtmlTableBegin);
+void AdminHtmlUtil::renderTableBegin(Buffer::Instance& response, absl::string_view name_column) {
+  response.add(absl::StrReplaceAll(AdminHtmlTableBegin, {{"@NAME_COLUMN@", name_column}}));
 }
 
 void AdminHtmlUtil::renderTableEnd(Buffer::Instance& response) { response.add(AdminHtmlTableEnd); }
@@ -201,9 +202,11 @@ void AdminHtmlUtil::renderEndpointTableRow(Buffer::Instance& response,
   // rather than an anchor tag. This should discourage crawlers that find the /
   // page from accidentally mutating all the server state by GETting all the hrefs.
   const char* method = handler.mutates_server_state_ ? "post" : "get";
-  if (submit_on_change) {
-    response.addFragments({"\n<tr><td><form action='", path, "' method='", method, "' id='", path,
-                           "' class='home-form'></form></td><td></td></tr>\n"});
+  if (submit_on_change || active) {
+    response.addFragments({"\n<tr><td><form ",
+                           active ? "onsubmit='return onSubmit()'"
+                                  : absl::StrCat("action='", path, "' method='", method, "'"),
+                           " id='", path, "' class='home-form'></form></td><td></td></tr>\n"});
   } else {
     response.addFragments({"\n<tr class='vert-space'><td></td><td></td></tr>\n<tr", row_class,
                            ">\n  <td class='home-data'>"});

source/server/admin/admin_html_util.h

@@ -47,7 +47,7 @@ class AdminHtmlUtil {
    * Renders the beginning of the help-table into the response buffer provided
    * in the constructor.
    */
-  static void renderTableBegin(Buffer::Instance&);
+  static void renderTableBegin(Buffer::Instance&, absl::string_view name_column);
 
   /**
    * Renders the end of the help-table into the response buffer provided in the

source/server/admin/html/BUILD

@@ -17,11 +17,12 @@ genrule(
         "admin.css",
         "active_params.html",
         "active_stats.js",
+        "histograms.js",
     ],
     outs = ["admin_html_gen.h"],
     cmd = "./$(location :generate_admin_html.sh) \
         $(location admin_head_start.html) $(location admin.css) $(location active_stats.js) \
-        $(location active_params.html) > $@",
+        $(location active_params.html) $(location histograms.js) > $@",
     tools = [":generate_admin_html.sh"],
 )
 

source/server/admin/html/active_params.html

@@ -1,8 +1,10 @@
 <tr class='gray'>
-  <td class='option'><input type='text' name='max-display-count' id='active-max-display-count' value=50 /></td>
+  <td class='option'><input type='text' name='max-display-count' id='active-max-display-count'
+                            value=50 onblur='updateParams()' /></td>
   <td class='home-data'><label for='active-max-display-count'>Maximum number of stats to display</label></td>
 </tr>
 <tr class='gray'>
-  <td class='option'><input type='text' name='update-interval' id='active-update-interval' value=5 /></td>
+  <td class='option'><input type='text' name='update-interval' id='active-update-interval'
+                            value=5 onblur='updateParams()' /></td>
   <td class='home-data'><label for='active-update-interval'>Number of seconds between each update</label></td>
 </tr>