From: William Lallemand <wlallemand@haproxy.com>
Date: Mon, 8 Dec 2025 17:05:36 +0000 (+0100)
Subject: BUG/MINOR: mworker/cli: 'show proc' is limited by buffer size
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2F20251208-show-proc-bufsize;p=thirdparty%2Fhaproxy.git

BUG/MINOR: mworker/cli: 'show proc' is limited by buffer size

In ticket #3204, it was reported that "show proc" is not able to display
more than 202 processes. Indeed the bufsize is 16k by default in the
master, and can't be changed anymore since 3.1.

This patch allows the 'show proc' to start again to dump when the buffer
is full, based on the timestamp of the last PID it attempted to dump.
Using pointers or count the number of processes might not be a good idea
since the list can change between calls.

Could be backported in all stable branche.
---

diff --git a/src/mworker.c b/src/mworker.c
index 86d959e8f..6aed15f3f 100644
--- a/src/mworker.c
+++ b/src/mworker.c
@@ -808,6 +808,7 @@ void mworker_cleanup_proc()
 
 struct cli_showproc_ctx {
 	int debug;
+	int next_uptime; /* uptime must be greater than this value */
 };
 
 /*  Displays workers and processes  */
@@ -825,23 +826,32 @@ static int cli_io_handler_show_proc(struct appctx *appctx)
 
 	chunk_reset(&trash);
 
-	memprintf(&reloadtxt, "%d [failed: %d]", proc_self->reloads, proc_self->failedreloads);
-	chunk_printf(&trash, "#%-14s %-15s %-15s %-15s %-15s", "<PID>", "<type>", "<reloads>", "<uptime>", "<version>");
-	if (ctx->debug)
-		chunk_appendf(&trash, "\t\t %-15s %-15s", "<ipc_fd[0]>", "<ipc_fd[1]>");
-	chunk_appendf(&trash, "\n");
-	memprintf(&uptime, "%dd%02dh%02dm%02ds", up / 86400, (up % 86400) / 3600, (up % 3600) / 60, (up % 60));
-	chunk_appendf(&trash, "%-15u %-15s %-15s %-15s %-15s", (unsigned int)getpid(), "master", reloadtxt, uptime, haproxy_version);
-	if (ctx->debug)
-		chunk_appendf(&trash, "\t\t %-15d %-15d", proc_self->ipc_fd[0], proc_self->ipc_fd[1]);
-	chunk_appendf(&trash, "\n");
+	if (ctx->next_uptime == 0) {
+		memprintf(&reloadtxt, "%d [failed: %d]", proc_self->reloads, proc_self->failedreloads);
+		chunk_printf(&trash, "#%-14s %-15s %-15s %-15s %-15s", "<PID>", "<type>", "<reloads>", "<uptime>", "<version>");
+		if (ctx->debug)
+			chunk_appendf(&trash, "\t\t %-15s %-15s", "<ipc_fd[0]>", "<ipc_fd[1]>");
+		chunk_appendf(&trash, "\n");
+
+		/* display the master only the first time */
+		memprintf(&uptime, "%dd%02dh%02dm%02ds", up / 86400, (up % 86400) / 3600, (up % 3600) / 60, (up % 60));
+		chunk_appendf(&trash, "%-15u %-15s %-15s %-15s %-15s", (unsigned int)getpid(), "master", reloadtxt, uptime, haproxy_version);
+		if (ctx->debug)
+			chunk_appendf(&trash, "\t\t %-15d %-15d", proc_self->ipc_fd[0], proc_self->ipc_fd[1]);
+		chunk_appendf(&trash, "\n");
+	}
 	ha_free(&reloadtxt);
 	ha_free(&uptime);
 
 	/* displays current processes */
-
-	chunk_appendf(&trash, "# workers\n");
+	if (ctx->next_uptime == 0)
+		chunk_appendf(&trash, "# workers\n");
 	list_for_each_entry(child, &proc_list, list) {
+
+		/* don't display current worker if we only need the next ones */
+		if (ctx->next_uptime != 0)
+			continue;
+
 		up = date.tv_sec - child->timestamp;
 		if (up < 0) /* must never be negative because of clock drift */
 			up = 0;
@@ -861,15 +871,21 @@ static int cli_io_handler_show_proc(struct appctx *appctx)
 		ha_free(&uptime);
 	}
 
-	/* displays old processes */
+	if (applet_putchk(appctx, &trash) == -1)
+		return 0;
 
-	if (old) {
-		chunk_appendf(&trash, "# old workers\n");
+	/* displays old processes */
+	if (old || ctx->next_uptime) { /* there's more */
+		if (ctx->next_uptime == 0)
+			chunk_appendf(&trash, "# old workers\n");
 		list_for_each_entry(child, &proc_list, list) {
 			up = date.tv_sec - child->timestamp;
 			if (up <= 0) /* must never be negative because of clock drift */
 				up = 0;
 
+			if (child->timestamp < ctx->next_uptime)
+				continue;
+
 			if (!(child->options & PROC_O_TYPE_WORKER))
 				continue;
 
@@ -881,12 +897,15 @@ static int cli_io_handler_show_proc(struct appctx *appctx)
 				chunk_appendf(&trash, "\n");
 				ha_free(&uptime);
 			}
+
+			/* start from there if there's not enough place */
+			ctx->next_uptime = child->timestamp;
+
+			if (applet_putchk(appctx, &trash) == -1)
+				return 0;
 		}
 	}
 
-	if (applet_putchk(appctx, &trash) == -1)
-		return 0;
-
 	/* dump complete */
 	return 1;
 }