From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [IPv6:2a0f:8001:1:32::40]) by lore.proxmox.com (Postfix) with ESMTPS id 830181FF0B0 for ; Tue, 27 Oct 2026 11:41:48 +0100 (CET) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id 1B0C321314; Tue, 27 Oct 2026 11:41:48 +0100 (CET) Message-ID: <30d7a066-cb68-419d-803e-eb4320906263@proxmox.com> Date: Tue, 27 Oct 2026 11:41:43 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH proxmox-backup 0/2] fix #7756: avoid qmp 'backup' timeout To: pbs-devel@lists.proxmox.com References: <20261026134559.352926-1-c.ebner@proxmox.com> Content-Language: en-US, de-DE From: Christian Ebner In-Reply-To: <20261026134559.352926-1-c.ebner@proxmox.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1793097703778 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.500 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) 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 Message-ID-Hash: 7Z257TVZ5X5LMQ46JO645CX3KTOCW5FK X-Message-ID-Hash: 7Z257TVZ5X5LMQ46JO645CX3KTOCW5FK X-MailFrom: c.ebner@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 10/26/26 2:46 PM, Christian Ebner wrote: > During high load due to parallel backups or slow storage backend on > the PBS, tokio blocking thread pool can become an issue. This is > because fetching of the previous snapshot manifest and index files > may be blocked in the blocking queue for a long time, leading to > exceeded QMP command timeout, especially notable for snapshots with > large index files. > > These patches optimize the async reader for content fetching and > draft a possible workaround by fully offloading the file download > handling to a dedicated thread, not offloading it to tokio's blocking > thread pool. > > Open question is whether it would make sense to distinguish between > API endpoints with higher priority and ones with lower priority in > general, and offload them to high priority and low priority thread > pools instead of spawning new threads on demand. > > Issue was raised again recently in the enterprise support and several > times in the community forum [0-2]. > > [0] https://forum.proxmox.com/threads/179304/ > [1] https://forum.proxmox.com/threads/183380/ > [2] https://forum.proxmox.com/threads/185679/ For completeness, this related issue which covers reworking the client side https://bugzilla.proxmox.com/show_bug.cgi?id=5080