From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id D50251FF16B for ; Fri, 7 Nov 2025 11:44:41 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 56061E2C9; Fri, 7 Nov 2025 11:45:23 +0100 (CET) Date: Fri, 07 Nov 2025 11:45:15 +0100 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= To: Proxmox Backup Server development discussion References: <20250904143735.125857-1-h.laimer@proxmox.com> In-Reply-To: <20250904143735.125857-1-h.laimer@proxmox.com> MIME-Version: 1.0 User-Agent: astroid/0.17.0 (https://github.com/astroidmail/astroid) Message-Id: <1762511147.2rj3dlqxrp.astroid@yuna.none> X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1762512298862 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.046 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. 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SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pbs-devel] [RFC proxmox{, -backup} 0/6] add support for configuring max 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: , Reply-To: Proxmox Backup Server development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" On September 4, 2025 4:37 pm, Hannes Laimer wrote: > This uses POSIX semaphores to control how many backups run at any given > time. Semaphores seemed like a fitting choice given the problem, so I > added a basic wrapper for named ones to proxmox-sys. Also, the changes > needed to add concurrency limits in PBS were minimal. > > A few questions I still have and would be great to get some feedback on, > - do we want to use semaphores like proposed here? Are there any good > reasons not to? they are rather primitive, and their file based nature means extra care is required to not accidentally reset or mishandle them. reconfiguring is also a bit of a pain, as you need to know the old value for certain to do so.. we already have shared memory based synchronization mechanisms in our Rust code, which would give us a lot more features.. e.g., allow things like registering queued backup sessions if there are no slots available, and notifying the oldest one if a slot becomes available.. this is currently used by the config version cache and the rate limiting code. or if we want to keep it really primitive, we already have a file-based operations tracking that we could extend, although that would probably require quite a bit of refactoring to make sense, since we currently do a lookup/write-operation registration as part of the backup session opening/connection upgrade.. > - should we include things like verify/gc/prune? Would an extra sem for > reading make sense(so separate limits for r and w, idk if there's a > use-case)? > > Nothing UI-wise is included, and for changes to apply the proxy has to > be restarted. Not sure if restarting the proxy is "ok-ish" ux wise, I > guess not :P But changing it involves re-creating the semaphore, which > is fine, just that there won't exist one for a really short time... what about reloading? we might still have sessions running in the old worker that are now no longer accounted for? > > > proxmox: > > Hannes Laimer (2): > sys: add wrapper for POSIX semaphores > pbs-api-types: add concurrency_limit to DataStoreConfig > > pbs-api-types/src/datastore.rs | 5 + > proxmox-sys/Cargo.toml | 1 + > proxmox-sys/src/lib.rs | 2 + > proxmox-sys/src/semaphore.rs | 164 +++++++++++++++++++++++++++++++++ > 4 files changed, 172 insertions(+) > create mode 100644 proxmox-sys/src/semaphore.rs > > > proxmox-backup: > > Hannes Laimer (4): > api: config: update/delete concurrency_limit on datastore > Cargo.toml: add 'semaphore' feature to proxmox-sys dep > bin: proxy: initialize concurrency semaphores for datastores > api: backup: wait for semaphore if one exists > > Cargo.toml | 2 +- > src/api2/backup/mod.rs | 24 ++++++++++++++++++++++-- > src/api2/config/datastore.rs | 9 +++++++++ > src/bin/proxmox-backup-proxy.rs | 11 +++++++++++ > 4 files changed, 43 insertions(+), 3 deletions(-) > > > Summary over all repositories: > 8 files changed, 215 insertions(+), 3 deletions(-) > > -- > Generated by git-murpp 0.8.1 > > > _______________________________________________ > pbs-devel mailing list > pbs-devel@lists.proxmox.com > https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel > > > _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel