UMA for data reduction proxy probe net errors

components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_settings.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
 #include "base/prefs/pref_member.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_auth_request_handler.h"
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_configurator.h"
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_params.h"
@@ skipping 25 matching lines @@
   CHANGE_EVENT_COUNT = 2 // This must always be last.
 };
 
 // Key of the UMA DataReductionProxy.StartupState histogram.
 const char kUMAProxyStartupStateHistogram[] =
     "DataReductionProxy.StartupState";
 
 // Key of the UMA DataReductionProxy.ProbeURL histogram.
 const char kUMAProxyProbeURL[] = "DataReductionProxy.ProbeURL";
 
+// Key of the UMA DataReductionProxy.ProbeURLNetError histogram.
+const char kUMAProxyProbeURLNetError[] = "DataReductionProxy.ProbeURLNetError";
+
 // Record a network change event.
 void RecordNetworkChangeEvent(DataReductionProxyNetworkChangeEvent event) {
   UMA_HISTOGRAM_ENUMERATION("DataReductionProxy.NetworkChangeEvents",
                             event,
                             CHANGE_EVENT_COUNT);
 }
 
 int64 GetInt64PrefValue(const base::ListValue& list_value, size_t index) {
   int64 val = 0;
   std::string pref_value;
@@ skipping 161 matching lines @@
     const net::URLFetcher* source) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // The purpose of sending a request for the warmup URL is to warm the
   // connection to the data_reduction_proxy. The result is ignored.
   if (source == warmup_fetcher_.get())
     return;
 
   DCHECK(source == fetcher_.get());
   net::URLRequestStatus status = source->GetStatus();
-  if (status.status() == net::URLRequestStatus::FAILED &&
-      status.error() == net::ERR_INTERNET_DISCONNECTED) {
-    RecordProbeURLFetchResult(INTERNET_DISCONNECTED);
-    return;
+  if (status.status() == net::URLRequestStatus::FAILED) {
+    if (status.error() == net::ERR_INTERNET_DISCONNECTED) {
+      RecordProbeURLFetchResult(INTERNET_DISCONNECTED);
+      return;
+    }
+    // TODO(bengr): Remove once we understand the reasons probes are failing.
+    // Probe errors are either due to fetcher-level errors or modified
+    // responses. This only tracks the former.
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        kUMAProxyProbeURLNetError, std::abs(status.error()));

[mmenke, 2014/07/25 18:27:00]

    UMA_HISTOGRAM_CUSTOM_ENUMERATION(kUMAProxyProbeURLNetError,
                                     std::abs(status.error()),
                                     net::GetAllErrorCodesForUma());

[Alexei Svitkine (slow), 2014/07/25 18:28:21]

No, sparse histogram is better in this case, as it avoids allocating a giant
array for all the possible net buckets.

   }
 
   std::string response;
   source->GetResponseAsString(&response);
 
   if ("OK" == response.substr(0, 2)) {
     DVLOG(1) << "The data reduction proxy is unrestricted.";
 
     if (enabled_by_user_) {
       if (restricted_by_carrier_) {
@@ skipping 329 matching lines @@
     SetProxyConfigs(enabled_by_user_,
                     IsDataReductionProxyAlternativeEnabled(),
                     restricted_by_carrier_,
                     false);
   }
   disabled_on_vpn_ = false;
   return false;
 }
 
 }  // namespace data_reduction_proxy