From: Thomas Lamprecht <t.lamprecht@proxmox.com>
To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>,
Stoiko Ivanov <s.ivanov@proxmox.com>
Subject: [pve-devel] applied-series: [PATCH http-server v3 0/4] improve error handling in accept_connections
Date: Thu, 10 Dec 2020 20:25:01 +0100 [thread overview]
Message-ID: <952fa8f6-2bf0-bca5-67b0-13d06ccbaa24@proxmox.com> (raw)
In-Reply-To: <20201210140251.6127-1-s.ivanov@proxmox.com>
On 10.12.20 15:02, Stoiko Ivanov wrote:
> v2->v3:
> * incorporated Thomas patient and excellent feedback (Thanks!!):
> * replaced the two error-flags by a single handle_creation flag, based
> on the observation that the code after AnyEvent::Handle->new() does not die
> (and that we'd probably still shutdown the socket if it did)
> * replaced the calls to shutdown($fh, SHUT_RD) with calls to close - in case
> accept() fails, we don't want to sent anything + it sents one tcp-packet less
> (only rst+ack, instead of fin+ack,rst+ack)
> * replaced syslog+dprint by a single warn (in our AnyEvent daemons that results
> in the line being printed to STDERR+to syslog with level warning)
> * squashed 1/5 (introduce dprint sub) and 5/5 (use it)
>
> tested on my workstation (the cleanup by having an deny-acl in
> /etc/default/pveproxy and connecting 1000 times with openssl s_client)
>
> original cover-letter for v2:
> v1->v2:
> * increment of connection count now happens right before the AnyEvent::Handle
> is created
> * the handle-creation is guarded by an error-flag, and if it fails the
> connection count is decremented (bounded to 0) again
> * as suggested by Thomas - added a debug print sub which includes the
> package name, linenumber and function name where the printing happens
> * refactored all active debug-prints to use it.
>
> original cover-letter for v1:
> This patchset is the result of investigating a report in our community forum:
> https://forum.proxmox.com/threads/pveproxy-eats-available-ram.79617/
>
> The first patch fixes an issue where pveproxy worker processes would never
> exit (and eat quite a bit of ram+cpu) when 'getpeername' returned an error.
>
> The second seemed to me like a sensible further cleanup, and the third patch
> will hopefully provide the needed information when debugging such things in
> the future.
>
> Huge thanks to Dominik, who analyzed this issue with me!
>
>
> Stoiko Ivanov (4):
> add debug print helper
> accept-phase: fix conn_count "leak"
> accept-phase: shutdown socket on early error
> add debug log for problems during accept
>
> PVE/APIServer/AnyEvent.pm | 68 ++++++++++++++++++++++++++++++---------
> 1 file changed, 53 insertions(+), 15 deletions(-)
>
applied series, much thanks!
prev parent reply other threads:[~2020-12-10 19:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 14:02 [pve-devel] " Stoiko Ivanov
2020-12-10 14:02 ` [pve-devel] [PATCH http-server v3 1/4] add debug print helper Stoiko Ivanov
2020-12-10 14:02 ` [pve-devel] [PATCH http-server v3 2/4] accept-phase: fix conn_count "leak" Stoiko Ivanov
2020-12-10 14:02 ` [pve-devel] [PATCH http-server v3 3/4] accept-phase: shutdown socket on early error Stoiko Ivanov
2020-12-10 14:02 ` [pve-devel] [PATCH http-server v3 4/4] add debug log for problems during accept Stoiko Ivanov
2020-12-10 19:25 ` Thomas Lamprecht [this message]
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