[
https://issues.apache.org/jira/browse/TS-4099?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15099213#comment-15099213
]
ASF GitHub Bot commented on TS-4099:
------------------------------------
Github user shukitchan commented on a diff in the pull request:
https://github.com/apache/trafficserver/pull/422#discussion_r49808951
--- Diff: cmd/traffic_manager/metrics.cc ---
@@ -0,0 +1,385 @@
+/** @file
+ *
+ * Traffic Manager custom metrics.
+ *
+ * @section license License
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ts/ink_config.h"
+#include "ts/ink_memory.h"
+#include "ts/Ptr.h"
+#include "ts/Vec.h"
+#include "ts/I_Layout.h"
+#include "bindings/bindings.h"
+#include "bindings/metrics.h"
+#include "I_RecCore.h"
+#include "MgmtDefs.h"
+#include "MgmtUtils.h"
+#include "WebOverview.h"
+#include "metrics.h"
+
+struct Evaluator {
+ Evaluator() : rec_name(NULL), data_type(RECD_NULL), ref(-1) {}
+
+ ~Evaluator()
+ {
+ ats_free(this->rec_name);
+ ink_release_assert(this->ref == -1);
+ }
+
+ bool
+ bind(lua_State *L, const char *metric, const char *expression)
+ {
+ if (RecGetRecordDataType(metric, &this->data_type) != REC_ERR_OKAY) {
+ return false;
+ }
+
+ this->rec_name = ats_strdup(metric);
+
+ switch (luaL_loadstring(L, expression)) {
+ case LUA_ERRSYNTAX:
+ case LUA_ERRMEM:
+ Debug("lua", "loadstring failed for %s", metric);
+ luaL_error(L, "invalid expression for %s", metric);
+ return false;
+ case 0:
+ break; // success
+ }
+
+ // The loaded chunk is now on the top of the stack. Stuff it into the
registry
+ // so we can evaluate it later.
+ this->ref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+ return true;
+ }
+
+ void
+ eval(lua_State *L) const
+ {
+ // Push the stashed expression chunk onto the stack.
+ lua_rawgeti(L, LUA_REGISTRYINDEX, this->ref);
+
+ // Evaluate it. Note that we don't emit a warning for
+ // evaluation errors. This is because not all metrics (eg.
+ // cache metrics) are available early in startup so we don't
+ // want to log spurious warning. Unfortunately it means that
+ // to check your config for errors you need to enable
+ // diagnostic tags.
+ lua_pushstring(L, this->rec_name);
+ if (lua_pcall(L, 1 /* nargs */, 1 /* nresults */, 0) != 0) {
+ Debug("lua", "failed to evaluate %s: %s", this->rec_name,
lua_tostring(L, -1));
+ lua_pop(L, 1);
+ return;
+ }
+
+ // If we got a return value, set it on the record. Records can return
nil to
+ // indicate they don't want to be set on this round.
+ if (!lua_isnil(L, -1)) {
+ RecData rec_value;
+
+ switch (this->data_type) {
+ case RECD_INT:
+ rec_value.rec_int = lua_tointeger(L, -1);
+ break;
+ case RECD_COUNTER:
+ rec_value.rec_counter = lua_tointeger(L, -1);
+ break;
+ case RECD_FLOAT:
+ // Lua will eval 0/0 to NaN rather than 0.
+ rec_value.rec_float = lua_tonumber(L, -1);
+ if (isnan(rec_value.rec_float)) {
+ rec_value.rec_float = 0.0;
+ }
+ break;
+ default:
+ goto done;
+ }
+
+ RecSetRecord(RECT_NULL, this->rec_name, this->data_type, &rec_value,
NULL, REC_SOURCE_EXPLICIT);
+ }
+
+ done:
+ // Pop the return value.
+ lua_pop(L, 1);
+ }
+
+private:
+ char *rec_name;
+ RecDataT data_type;
+
+ int ref;
+};
+
+struct EvaluatorList {
+ EvaluatorList() : update(true), passes(0) {}
+ ~EvaluatorList()
+ {
+ forv_Vec(Evaluator, e, this->evaluators) { delete e; }
+ }
+
+ void
+ push_back(Evaluator *e)
+ {
+ evaluators.push_back(e);
+ }
+
+ void
+ evaluate(lua_State *L) const
+ {
+ ink_hrtime start = ink_get_hrtime_internal();
+ ink_hrtime elapsed;
+
+ forv_Vec(Evaluator, e, this->evaluators) { e->eval(L); }
+
+ elapsed = ink_hrtime_diff(ink_get_hrtime_internal(), start);
+ Debug("lua", "evaluated %u metrics in %fmsec", evaluators.length(),
ink_hrtime_to_usec(elapsed) / 1000.0);
+ }
+
+ bool update;
+ int64_t passes;
+ Vec<Evaluator *> evaluators;
+};
+
+static int
+update_metrics_namespace(lua_State *L)
+{
+ lua_Integer count;
+
+ lua_metrics_install(L);
+ count = lua_tointeger(L, 1);
+ lua_pop(L, 1);
+
+ return count;
+}
+
+static int64_t
+timestamp_now_msec()
+{
+ ink_hrtime now = ink_get_hrtime_internal();
+ return ink_hrtime_to_msec(now);
+}
+
+static int
+metrics_register_evaluator(lua_State *L)
+{
+ const char *metric;
+ const char *chunk;
+ Evaluator *eval;
+ EvaluatorList *evaluators;
+ BindingInstance *binding = BindingInstance::self(L);
+
+ // The metric name is the first upvalue (from the record creation
closure).
+ metric = lua_tostring(L, lua_upvalueindex(1));
+ // The evaluation chunk is the (only) argument.
+ chunk = lua_tostring(L, -1);
+
+ binding = BindingInstance::self(L);
+ evaluators = (EvaluatorList *)binding->retrieve_ptr("evaluators");
+
+ ink_release_assert(evaluators != NULL);
+
+ eval = new Evaluator();
+ eval->bind(L, metric, chunk);
+
+ evaluators->push_back(eval);
+ return 0;
+}
+
+static int
+metrics_create_record(lua_State *L, RecDataT data_type)
+{
+ const char *name;
+ RecT rec_type = RECT_NULL;
+ int error = REC_ERR_FAIL;
+
+ BindingInstance::typecheck(L, "record.create", LUA_TSTRING, LUA_TNONE);
+
+ // Get the name of the record to create.
+ name = lua_tostring(L, -1);
+
+ if (strncmp(name, "proxy.process.", sizeof("proxy.process.") - 1) == 0) {
+ rec_type = RECT_PROCESS;
+ } else if (strncmp(name, "proxy.node.", sizeof("proxy.node.") - 1) == 0)
{
+ rec_type = RECT_NODE;
+ } else if (strncmp(name, "proxy.cluster.", sizeof("proxy.cluster.") - 1)
== 0) {
+ rec_type = RECT_CLUSTER;
+ }
+
+ // You have to follow the naming convention.
+ if (rec_type == RECT_NULL) {
+ luaL_error(L, "invalid metric name '%s'", name);
+ }
+
+ switch (data_type) {
+ case RECD_INT:
+ error = RecRegisterStatInt(rec_type, name, 0, RECP_NON_PERSISTENT);
+ break;
+ case RECD_FLOAT:
+ error = RecRegisterStatFloat(rec_type, name, 0, RECP_NON_PERSISTENT);
+ break;
+ case RECD_COUNTER:
+ error = RecRegisterStatCounter(rec_type, name, 0, RECP_NON_PERSISTENT);
+ break;
+ default:
+ break;
+ }
+
+ if (error != REC_ERR_OKAY) {
+ luaL_error(L, "failed to register metric '%s'", name);
+ }
+
+ // Push a copy of the metric name onto the stack.
+ lua_pushvalue(L, -1);
+ // Push the Evaluator as a closure with the metric name as an upvalue.
+ lua_pushcclosure(L, metrics_register_evaluator, 1);
+
+ Debug("lua", "registered %s as record type %d", name, rec_type);
+ return 1;
+}
+
+static int
+metrics_create_integer(lua_State *L)
+{
+ return metrics_create_record(L, RECD_INT);
+}
+
+static int
+metrics_create_counter(lua_State *L)
+{
+ return metrics_create_record(L, RECD_COUNTER);
+}
+
+static int
+metrics_create_float(lua_State *L)
+{
+ return metrics_create_record(L, RECD_FLOAT);
+}
+
+static int
+metrics_cluster_sum(lua_State *L)
+{
+ const char *rec_name;
+ RecDataT data_type;
+ RecData rec_data;
+
+ // Get the name of the record to sum.
+ rec_name = lua_tostring(L, -1);
+
+ // XXX Check whether we have a cached value for this somewhere ...
+
+ // If not, get the record data type.
+ if (RecGetRecordDataType(rec_name, &data_type) == REC_ERR_FAIL) {
+ luaL_error(L, "unknown metric name '%s'", rec_name);
+ }
+
+ // Sum the cluster value.
+ if (!overviewGenerator->varClusterDataFromName(data_type, rec_name,
&rec_data)) {
+ RecDataClear(data_type, &rec_data);
+
+ // If we can't get any cluster data, return nil. This will generally
cause the
+ // evaluator to fail, which is handled by logging and ignoring the
failure.
+ lua_pushnil(L);
+ return 1;
+ }
+
+ switch (data_type) {
+ case RECD_INT: /* fallthru */
+ case RECD_COUNTER:
+ lua_pushinteger(L, rec_data.rec_int);
+ break;
+ case RECD_FLOAT:
+ lua_pushnumber(L, rec_data.rec_float);
+ break;
+ case RECD_STRING:
+ lua_pushlstring(L, rec_data.rec_string, strlen(rec_data.rec_string));
+ break;
+ default:
+ lua_pushnil(L);
+ }
+
+ // Return 1 value on the stack.
+ return 1;
+}
+
+bool
+metrics_binding_initialize(BindingInstance &binding)
+{
+ ats_scoped_str sysconfdir(RecConfigReadConfigDir());
+ ats_scoped_str config(Layout::get()->relative_to(sysconfdir,
"metrics.config"));
+
+ if (!binding.construct()) {
+ mgmt_fatal(stderr, 0, "failed to initialize Lua runtime\n");
+ }
+
+ // Register the metrics userdata type.
+ lua_metrics_register(binding.lua);
+ update_metrics_namespace(binding.lua);
+
+ // Register our own API.
+ binding.bind_function("integer", metrics_create_integer);
+ binding.bind_function("counter", metrics_create_counter);
+ binding.bind_function("float", metrics_create_float);
+ binding.bind_function("metrics.cluster.sum", metrics_cluster_sum);
+
+ binding.bind_constant("metrics.now.msec", timestamp_now_msec());
+ binding.bind_constant("metrics.update.pass", int64_t(0));
+
+ // Stash a backpointer to the evaluators.
+ binding.attach_ptr("evaluators", new EvaluatorList());
+
+ // Finally, execute the config file.
+ if (binding.require(config.get())) {
+ return true;
+ }
+
+ return false;
+}
+
+void
+metrics_binding_destroy(BindingInstance &binding)
+{
+ EvaluatorList *evaluators;
+
+ evaluators = (EvaluatorList *)binding.retrieve_ptr("evaluators");
+ binding.attach_ptr("evaluators", NULL);
+ delete evaluators;
+}
+
+void
+metrics_binding_evaluate(BindingInstance &binding)
+{
+ EvaluatorList *evaluators;
+
+ evaluators = (EvaluatorList *)binding.retrieve_ptr("evaluators");
+ ink_release_assert(evaluators != NULL);
+
+ // Keep updating the namespace until it settles (ie. we make 0 updates).
+ if (evaluators->update) {
+ evaluators->update = update_metrics_namespace(binding.lua) ? true :
false;
+ }
+
+ binding.bind_constant("metrics.now.msec", timestamp_now_msec());
+ binding.bind_constant("metrics.update.pass", ++evaluators->passes);
+ evaluators->evaluate(binding.lua);
+
+ // Periodically refresh the namespace to catch newly added metrics.
+ if (evaluators->passes % 10 == 0) {
--- End diff --
Is this going to be too heavy for every 10 evaluate() ?
so for every 10 evaluate, we then rerun lua_metrics_install()?
do we really need this given that metrics_binding_initialize() will also
call update_metrics_namespace()/lua_metrics_install()?
Perhaps I don't understand this part correctly.
> replace XML statistics with Lua
> -------------------------------
>
> Key: TS-4099
> URL: https://issues.apache.org/jira/browse/TS-4099
> Project: Traffic Server
> Issue Type: New Feature
> Components: Lua, Manager, Metrics
> Reporter: James Peach
> Assignee: James Peach
> Fix For: 6.2.0
>
>
> The custom metrics XML format is undocumented and difficult to use and
> extend. Since we plan to use Lua for configuration programmability, lets make
> a start by replacing this subsystem with Lua.
> It turns out that Lua is mostly more readable and easier to understand.
> Performance is roughly similar.
> Example syntax:
> {code}
> float 'proxy.node.user_agent_total_bytes_avg_10s' [[
> local self = ...
> return interval_delta_of_10s(self, function()
> return proxy.node.user_agent_total_bytes
> end)
> ]]
> counter 'proxy.node.origin_server_total_bytes' [[
> return proxy.node.http.origin_server_total_request_bytes +
> proxy.node.http.origin_server_total_response_bytes +
> proxy.node.http.parent_proxy_total_request_bytes +
> proxy.node.http.parent_proxy_total_response_bytes
> ]]
> {code}
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