server: metrics: add llamacpp:prompt_seconds_total and llamacpp:tokens_predicted_seconds_total, reset bucket only on /metrics. Fix values cast to int. Add Process-Start-Time-Unix header. (#5937)

Closes #5850

examples/server/server.cpp

@@ -335,8 +335,12 @@ struct server_slot {
 };
 
 struct server_metrics {
+    const int64_t t_start = ggml_time_us();
+
     uint64_t n_prompt_tokens_processed_total = 0;
+    uint64_t t_prompt_processing_total       = 0;
     uint64_t n_tokens_predicted_total        = 0;
+    uint64_t t_tokens_generation_total       = 0;
 
     uint64_t n_prompt_tokens_processed = 0;
     uint64_t t_prompt_processing       = 0;
@@ -348,12 +352,14 @@ struct server_metrics {
         n_prompt_tokens_processed_total += slot.n_prompt_tokens_processed;
         n_prompt_tokens_processed       += slot.n_prompt_tokens_processed;
         t_prompt_processing             += slot.t_prompt_processing;
+        t_prompt_processing_total       += slot.t_prompt_processing;
     }
 
     void on_prediction(const server_slot &slot) {
-        n_tokens_predicted_total += slot.n_decoded;
-        n_tokens_predicted       += slot.n_decoded;
-        t_tokens_generation      += slot.t_token_generation;
+        n_tokens_predicted_total   += slot.n_decoded;
+        n_tokens_predicted         += slot.n_decoded;
+        t_tokens_generation        += slot.t_token_generation;
+        t_tokens_generation_total  += slot.t_token_generation;
     }
 
     void reset_bucket() {
@@ -1502,9 +1508,12 @@ struct server_context {
                         { "idle",                            n_idle_slots       },
                         { "processing",                      n_processing_slots },
                         { "deferred",                        queue_tasks.queue_tasks_deferred.size() },
+                        { "t_start",                         metrics.t_start},
 
                         { "n_prompt_tokens_processed_total", metrics.n_prompt_tokens_processed_total},
+                        { "t_tokens_generation_total",       metrics.t_tokens_generation_total},
                         { "n_tokens_predicted_total",        metrics.n_tokens_predicted_total},
+                        { "t_prompt_processing_total",       metrics.t_prompt_processing_total},
 
                         { "n_prompt_tokens_processed",       metrics.n_prompt_tokens_processed},
                         { "t_prompt_processing",             metrics.t_prompt_processing},
@@ -1517,7 +1526,9 @@ struct server_context {
                         { "slots",                           slots_data },
                     };
 
-                    metrics.reset_bucket();
+                    if (json_value(task.data, "reset_bucket", false)) {
+                        metrics.reset_bucket();
+                    }
                     queue_results.send(res);
                 } break;
         }
@@ -2709,6 +2720,7 @@ int main(int argc, char ** argv) {
             task.id_multi  = -1;
             task.id_target = -1;
             task.type = SERVER_TASK_TYPE_METRICS;
+            task.data.push_back({{"reset_bucket", true}});
 
             ctx_server.queue_results.add_waiting_task_id(task.id);
             ctx_server.queue_tasks.post(task);
@@ -2732,20 +2744,28 @@ int main(int argc, char ** argv) {
                 {"counter", {{
                         {"name",  "prompt_tokens_total"},
                         {"help",  "Number of prompt tokens processed."},
-                        {"value",  data["n_prompt_tokens_processed_total"]}
+                        {"value",  (uint64_t) data["n_prompt_tokens_processed_total"]}
+                }, {
+                        {"name",  "prompt_seconds_total"},
+                        {"help",  "Prompt process time"},
+                        {"value",  (uint64_t) data["t_prompt_processing_total"] / 1.e3}
                 }, {
                         {"name",  "tokens_predicted_total"},
                         {"help",  "Number of generation tokens processed."},
-                        {"value",  data["n_tokens_predicted_total"]}
+                        {"value",  (uint64_t) data["n_tokens_predicted_total"]}
+                }, {
+                        {"name",  "tokens_predicted_seconds_total"},
+                        {"help",  "Predict process time"},
+                        {"value",  (uint64_t) data["t_tokens_generation_total"] / 1.e3}
                 }}},
                 {"gauge", {{
                         {"name",  "prompt_tokens_seconds"},
                         {"help",  "Average prompt throughput in tokens/s."},
-                        {"value",  n_prompt_tokens_processed ? 1e3 / t_prompt_processing * n_prompt_tokens_processed : 0}
+                        {"value",  n_prompt_tokens_processed ? 1.e3 / t_prompt_processing * n_prompt_tokens_processed : 0.}
                 },{
                         {"name",  "predicted_tokens_seconds"},
                         {"help",  "Average generation throughput in tokens/s."},
-                        {"value",  n_tokens_predicted ? 1e3 / t_tokens_generation * n_tokens_predicted : 0}
+                        {"value",  n_tokens_predicted ? 1.e3 / t_tokens_generation * n_tokens_predicted : 0.}
                 },{
                         {"name",  "kv_cache_usage_ratio"},
                         {"help",  "KV-cache usage. 1 means 100 percent usage."},
@@ -2753,15 +2773,15 @@ int main(int argc, char ** argv) {
                 },{
                         {"name",  "kv_cache_tokens"},
                         {"help",  "KV-cache tokens."},
-                        {"value",  data["kv_cache_tokens_count"]}
+                        {"value",  (uint64_t) data["kv_cache_tokens_count"]}
                 },{
                         {"name",  "requests_processing"},
                         {"help",  "Number of request processing."},
-                        {"value",  data["processing"]}
+                        {"value",  (uint64_t) data["processing"]}
                 },{
                         {"name",  "requests_deferred"},
                         {"help",  "Number of request deferred."},
-                        {"value",  data["deferred"]}
+                        {"value",  (uint64_t) data["deferred"]}
                 }}}
             };
 
@@ -2775,13 +2795,16 @@ int main(int argc, char ** argv) {
                     const std::string name = metric_def["name"];
                     const std::string help = metric_def["help"];
 
-                    auto value = json_value(metric_def, "value", 0);
+                    auto value = json_value(metric_def, "value", 0.);
                     prometheus << "# HELP llamacpp:" << name << " " << help  << "\n"
                                << "# TYPE llamacpp:" << name << " " << type  << "\n"
                                << "llamacpp:"        << name << " " << value << "\n";
                 }
             }
 
+            const int64_t t_start = data["t_start"];
+            res.set_header("Process-Start-Time-Unix", std::to_string(t_start));
+
             res.set_content(prometheus.str(), "text/plain; version=0.0.4");
             res.status = 200; // HTTP OK
         });

examples/server/tests/features/server.feature

@@ -29,6 +29,7 @@ Feature: llama.cpp server
     And   a completion request with no api error
     Then  <n_predicted> tokens are predicted matching <re_content>
     And   prometheus metrics are exposed
+    And   metric llamacpp:tokens_predicted is <n_predicted>
 
     Examples: Prompts
       | prompt                           | n_predict | re_content                       | n_predicted |

examples/server/tests/features/steps/steps.py

@@ -586,14 +586,24 @@ async def step_prometheus_metrics_exported(context):
             metric_exported = False
             if context.debug:
                 print(f"/metrics answer:\n{metrics_raw}\n")
+            context.metrics = {}
             for metric in parser.text_string_to_metric_families(metrics_raw):
                 match metric.name:
                     case "llamacpp:kv_cache_usage_ratio":
                         assert len(metric.samples) > 0
                         metric_exported = True
+                context.metrics[metric.name] = metric
+            assert int(metrics_response.headers["Process-Start-Time-Unix"]) > 0, "no header process start time"
             assert metric_exported, "No metrics exported"
 
 
+@step(u'metric {metric_name} is {metric_value:d}')
+def step_assert_metric_value(context, metric_name, metric_value):
+    if metric_name not in context.metrics:
+        assert False, f"no metric {metric_name} in {context.metrics.keys()}"
+    assert context.metrics[metric_name].samples[0].value == metric_value, f"metric: {context.metrics[metric_name]}"
+
+
 @step(u'available models')
 def step_available_models(context):
     # openai client always expects an api_key
@@ -879,7 +889,6 @@ def assert_n_tokens_predicted(completion_response, expected_predicted_n=None, re
                                                      f' {n_predicted} <> {expected_predicted_n}')
 
 
-
 async def gather_tasks_results(context):
     n_tasks = len(context.concurrent_tasks)
     if context.debug: