From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 33282717AA for ; Thu, 8 Apr 2021 14:28:22 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 1EC711B381 for ; Thu, 8 Apr 2021 14:28:22 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 8911A1B379 for ; Thu, 8 Apr 2021 14:28:21 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 47B78459FA for ; Thu, 8 Apr 2021 14:28:21 +0200 (CEST) From: Dominik Csapak To: pbs-devel@lists.proxmox.com Date: Thu, 8 Apr 2021 14:28:20 +0200 Message-Id: <20210408122820.13492-1-d.csapak@proxmox.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.167 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pbs-devel] [RFC PATCH proxmox-backup] tools/async_io: do not error on Accept for StaticIncoming X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Apr 2021 12:28:22 -0000 in proxmox-backup-proxy, we log and discard any errors on 'accept', so that we can continue to server requests in proxmox-backup-api, we just have the StaticIncoming that accepts, which will forward any errors from the underlying TcpListener this patch also logs and discards the errors, like in the proxy. Otherwise it could happen that if the api-daemon has more files open than the proxy, it will shut itself down because of a 'too many open files' error if there are many open connections (the service should also restart on exit i think, but this is a separate issue) Signed-off-by: Dominik Csapak --- two remaining issues/questions: 1. maybe we want an accept loop in proxmox-backup-api akin to the one in the proxy? this way we have better locality of the error logging, more control of e.g. how many connections we accept, etc. 2. is it wise to log every failed connection attempt? i can very easily generate massive logspam with a single line of 'ab'. shouldn't we e.g. only log once a second how many connections were not accepted? this is for the api as well as the proxy src/tools/async_io.rs | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/tools/async_io.rs b/src/tools/async_io.rs index 997c02fa..844afaa9 100644 --- a/src/tools/async_io.rs +++ b/src/tools/async_io.rs @@ -6,6 +6,7 @@ use std::pin::Pin; use std::task::{Context, Poll}; use futures::stream::{Stream, TryStream}; +use futures::ready; use tokio::io::{AsyncRead, AsyncWrite, ReadBuf}; use tokio::net::TcpListener; use hyper::client::connect::Connection; @@ -108,10 +109,15 @@ impl hyper::server::accept::Accept for StaticIncoming { self: Pin<&mut Self>, cx: &mut Context, ) -> Poll>> { - match self.get_mut().0.poll_accept(cx) { - Poll::Pending => Poll::Pending, - Poll::Ready(Ok((conn, _addr))) => Poll::Ready(Some(Ok(conn))), - Poll::Ready(Err(err)) => Poll::Ready(Some(Err(err))), + let this = self.get_mut(); + loop { + match ready!(this.0.poll_accept(cx)) { + Ok((conn, _addr)) => return Poll::Ready(Some(Ok(conn))), + Err(err) => { + eprintln!("error accepting connection: {}", err); + continue; + } + } } } } -- 2.20.1