From 45441f9924761e681d5d599f0ee0f13adbc84249 Mon Sep 17 00:00:00 2001 From: Hannes Mehnert Date: Tue, 28 Nov 2023 22:26:50 +0100 Subject: [PATCH] fix --- Posts/TCP-ns | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Posts/TCP-ns b/Posts/TCP-ns index b2b0e4a..d577190 100644 --- a/Posts/TCP-ns +++ b/Posts/TCP-ns @@ -39,7 +39,7 @@ Now, after switching over to µTCP, graphed below, there's much fewer network ut Investigating the involved parts showed that a TCP connection that was never established has been registered at the MirageOS layer, but the pure core does not expose an event from the received RST that the connection has been cancelled. This means the MirageOS layer piles up all the connection attempts, and doesn't inform the application that the connection couldn't be established. Once this was well understood, developing the [required code changes](https://github.com/robur-coop/utcp/commit/67fc49468e6b75b96a481ebe44dd11ce4bb76e6c) was straightforward. The graph shows that the fix was deployed at 15:25. The memory usage is constant afterwards, but the network utilization increased enormously. -[](/static/img/a.ns.utcp-utcp.png) +[](/static/img/a.ns.utcp-ev.png) Now, the network utilization is unwanted. This was hidden by the application waiting forever that the TCP connection getting established. Our bugfix uncovered another issue, a tight loop: - the nameserver attempts to connect to the other nameserver (`request`);