From 19f580925862dcc2d57ab1310de184c8d30de98f Mon Sep 17 00:00:00 2001 From: Joris Baum Date: Thu, 20 Aug 2026 09:43:38 +0200 Subject: [PATCH 1/5] Refine phrasing and examples for newly added types I took a deeper look to double check and adjusted as per my findings --- deploy-apps/streaming-logs.html.md.erb | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/deploy-apps/streaming-logs.html.md.erb b/deploy-apps/streaming-logs.html.md.erb index 2bf794e1..8bda663e 100644 --- a/deploy-apps/streaming-logs.html.md.erb +++ b/deploy-apps/streaming-logs.html.md.erb @@ -146,16 +146,22 @@ For example: ### HEALTH -The Diego Cell emits `HEALTH` logs when running health check actions for an app. These logs are generated by the health check binary that monitors app instances. By default, health check log output is suppressed unless an error occurs. +The Diego Cell emits `HEALTH` logs for health check activity on an app. This inlcudes lifecycle events as well as monitoring start and health-state transitions. + +For example: + +
+2026-01-26T13:49:18.72+0000 [HEALTH/0]   OUT Container passed the readiness health check. Container marked ready and added to route pool.
+
### PROXY -Every app container includes an Envoy sidecar proxy that handles the mTLS handshake with the Gorouter and proxies traffic to the app process. The Envoy sidecar emits `PROXY` logs. By default, Envoy runs with a critical log level, so `PROXY` logs mainly appear when Envoy encounters critical errors, fails to start, or is killed due to the container running out of memory. +Every app container includes an Envoy sidecar proxy that handles the mTLS handshake with the Gorouter and proxies traffic to the app process. The Envoy sidecar emits `PROXY` logs. By default, Envoy runs with a critical log level, so you rarely see `PROXY` logs. They mainly appear when Envoy exits or is killed, such as when the container runs out of memory. For example: 
-2026-01-26T13:49:18.72+0000 [PROXY/0]     OUT Exit status 137 (out of memory)
+2026-01-26T13:49:18.72+0000 [PROXY/0]     OUT Exit status 137
@@ -261,4 +267,4 @@ If you are developing a client that displays a stream of <%= vars.app_runtime_ab

By changing the Java log output, you can force your app to reformat stack trace messages, replacing newline characters with a token. Set your log parsing code to replace that token with newline characters again to display the - logs properly in Kibana. \ No newline at end of file + logs properly in Kibana. From 3c71eb11b3b6d7a2bc040824c3cbb6bfe461f18c Mon Sep 17 00:00:00 2001 From: Joris Baum Date: Thu, 20 Aug 2026 09:45:06 +0200 Subject: [PATCH 2/5] Add note on STATS source type --- deploy-apps/streaming-logs.html.md.erb | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/deploy-apps/streaming-logs.html.md.erb b/deploy-apps/streaming-logs.html.md.erb index 8bda663e..95cb81fb 100644 --- a/deploy-apps/streaming-logs.html.md.erb +++ b/deploy-apps/streaming-logs.html.md.erb @@ -164,6 +164,11 @@ For example: 2026-01-26T13:49:18.72+0000 [PROXY/0] OUT Exit status 137 +

+Note +You might also see STATS entries in a syslog drain. These are container metrics, not a log type, and only appear when the drain is configured with drain-data=metrics or drain-data=all. Because they are metrics, STATS entries cannot be filtered by source type. +

+ ## Writing to the log from your app From fe5404a864ea1769a60b8f54b82905e649ffa762 Mon Sep 17 00:00:00 2001 From: Joris Baum Date: Fri, 21 Aug 2026 11:09:31 +0200 Subject: [PATCH 3/5] Bring critical error part back --- deploy-apps/streaming-logs.html.md.erb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/deploy-apps/streaming-logs.html.md.erb b/deploy-apps/streaming-logs.html.md.erb index 95cb81fb..2bf87249 100644 --- a/deploy-apps/streaming-logs.html.md.erb +++ b/deploy-apps/streaming-logs.html.md.erb @@ -156,7 +156,7 @@ For example: ### PROXY -Every app container includes an Envoy sidecar proxy that handles the mTLS handshake with the Gorouter and proxies traffic to the app process. The Envoy sidecar emits `PROXY` logs. By default, Envoy runs with a critical log level, so you rarely see `PROXY` logs. They mainly appear when Envoy exits or is killed, such as when the container runs out of memory. +Every app container includes an Envoy sidecar proxy that handles the mTLS handshake with the Gorouter and proxies traffic to the app process. The Envoy sidecar emits `PROXY` logs. By default, Envoy runs with a critical log level, so you rarely see `PROXY` logs. They mainly appear when Envoy encounters a critical error or is killed, such as when the container runs out of memory. For example: From cda112a6ae42256aca6d5e90a6636d0d61060c7c Mon Sep 17 00:00:00 2001 From: Joris Baum Date: Fri, 21 Aug 2026 11:17:31 +0200 Subject: [PATCH 4/5] Emit logs for activity of an app, not on --- deploy-apps/streaming-logs.html.md.erb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/deploy-apps/streaming-logs.html.md.erb b/deploy-apps/streaming-logs.html.md.erb index 2bf87249..7fa0da4f 100644 --- a/deploy-apps/streaming-logs.html.md.erb +++ b/deploy-apps/streaming-logs.html.md.erb @@ -146,7 +146,7 @@ For example: ### HEALTH -The Diego Cell emits `HEALTH` logs for health check activity on an app. This inlcudes lifecycle events as well as monitoring start and health-state transitions. +The Diego Cell emits `HEALTH` logs for health check activity of an app. This inlcudes lifecycle events as well as monitoring start and health-state transitions. For example: From ddfde5bf7e96a6b6458ff309f9f94a43832e4806 Mon Sep 17 00:00:00 2001 From: Joris Baum Date: Fri, 21 Aug 2026 11:20:13 +0200 Subject: [PATCH 5/5] Bring back documenting default behavior of HEALTH --- deploy-apps/streaming-logs.html.md.erb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/deploy-apps/streaming-logs.html.md.erb b/deploy-apps/streaming-logs.html.md.erb index 7fa0da4f..eeb6ac96 100644 --- a/deploy-apps/streaming-logs.html.md.erb +++ b/deploy-apps/streaming-logs.html.md.erb @@ -146,7 +146,7 @@ For example: ### HEALTH -The Diego Cell emits `HEALTH` logs for health check activity of an app. This inlcudes lifecycle events as well as monitoring start and health-state transitions. +The Diego Cell emits `HEALTH` logs for health check activity of an app. This inlcudes lifecycle events as well as monitoring start and health-state transitions. By default, the per-probe output of the health check is not logged; the Diego Cell logs health-check lifecycle events such as monitoring start and health-state transitions. For example: