From 6832fd7fd7642056ffdf892c1c20bacf25a72b91 Mon Sep 17 00:00:00 2001
From: Ben Reedy <breed808@breed808.com>
Date: Sun, 29 May 2022 11:00:37 +1000
Subject: [PATCH] feat!: Disable IIS queries in `process` collector

IIS queries are disabled by default, and can be enabled with the
`--collector.process.iis=true` flag.

These WMI queries are suspected to be one source of virtual memory leaks
in the exporter.

These WMI queries are also responsible for timeouts on some hosts.

Signed-off-by: Ben Reedy <breed808@breed808.com>
---
 collector/process.go      | 25 ++++++++++++++++++-------
 docs/collector.process.md |  7 +++++++
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/collector/process.go b/collector/process.go
index 7ce5f23d..2fb2846d 100644
--- a/collector/process.go
+++ b/collector/process.go
@@ -34,6 +34,8 @@ var (
 
 	processIncludeSet bool
 	processExcludeSet bool
+
+	enableWorkerProcess *bool
 )
 
 type processCollector struct {
@@ -77,6 +79,11 @@ func newProcessCollectorFlags(app *kingpin.Application) {
 		return nil
 	}).String()
 
+	enableWorkerProcess = kingpin.Flag(
+		"collector.process.iis",
+		"Enable IIS worker process name queries. May cause the collector to leak memory.",
+	).Default("false").Bool()
+
 	processOldInclude = app.Flag(
 		FlagProcessOldInclude,
 		"DEPRECATED: Use --collector.process.include",
@@ -255,9 +262,11 @@ func (c *processCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metr
 	}
 
 	var dst_wp []WorkerProcess
-	q_wp := queryAll(&dst_wp, c.logger)
-	if err := wmi.QueryNamespace(q_wp, &dst_wp, "root\\WebAdministration"); err != nil {
-		_ = level.Debug(c.logger).Log("msg", fmt.Sprintf("Could not query WebAdministration namespace for IIS worker processes: %v. Skipping", err))
+	if *enableWorkerProcess {
+		q_wp := queryAll(&dst_wp, c.logger)
+		if err := wmi.QueryNamespace(q_wp, &dst_wp, "root\\WebAdministration"); err != nil {
+			_ = level.Debug(c.logger).Log(fmt.Sprintf("Could not query WebAdministration namespace for IIS worker processes: %v. Skipping\n", err))
+		}
 	}
 
 	for _, process := range data {
@@ -271,10 +280,12 @@ func (c *processCollector) Collect(ctx *ScrapeContext, ch chan<- prometheus.Metr
 		pid := strconv.FormatUint(uint64(process.IDProcess), 10)
 		cpid := strconv.FormatUint(uint64(process.CreatingProcessID), 10)
 
-		for _, wp := range dst_wp {
-			if wp.ProcessId == uint64(process.IDProcess) {
-				processName = strings.Join([]string{processName, wp.AppPoolName}, "_")
-				break
+		if *enableWorkerProcess {
+			for _, wp := range dst_wp {
+				if wp.ProcessId == uint64(process.IDProcess) {
+					processName = strings.Join([]string{processName, wp.AppPoolName}, "_")
+					break
+				}
 			}
 		}
 
diff --git a/docs/collector.process.md b/docs/collector.process.md
index fc970482..51109d9a 100644
--- a/docs/collector.process.md
+++ b/docs/collector.process.md
@@ -11,6 +11,7 @@ Enabled by default? | No
 
 ## Flags
 
+<<<<<<< HEAD
 ### `--collector.process.include`
 
 Regexp of processes to include. Process name must both match `include` and not
@@ -23,6 +24,12 @@ Regexp of processes to exclude. Process name must both match `include` and not
 match `exclude` to be included. Recommended to keep down number of returned
 metrics.
 
+### `--collector.process.iis`
+
+Enables IIS process name queries. IIS process names are combined with their app pool name to form the `process` label.
+
+Disabled by default, and can be enabled with `--collector.process.iis=true`.
+
 ### Example
 To match all firefox processes: `--collector.process.include="firefox.*"`.
 Note that multiple processes with the same name will be disambiguated by