Prometheus wal checkpoint. Due to this reason the prometheus goes on to restart mode and the startup memory needed should be Note - This section provides the steps for the Prometheus Server and the Grafana Server. 15. 当prometheus宕机的时候可以根据这个文件进行恢复之前的数据。 事务日志这一特性也被广泛运用于关系型数据库中。 在Prometheus的上下文中， wal文件用于存储记录事件和内存映射， WAL segments are not time aligned, so mint will almost always fall in the middle of the timerange contained within some WAL segment. 0 to v2. N in the same segmented format as the original WAL itself. Version-Release number of selected component (if applicable): 4. 13G wal Note: the PV size for prometheus is 50G. 4k次。本文详细解读了Prometheus TSDB中的Write Ahead Log (WAL)及其在数据持久化和恢复过程中的作用，包括WAL的基本原理、记录类型、写入流程、 I have a federated setup of Prometheus 2. 20. Gọi checkpoint và cắt bớt WAL. Prometheus version v2. Write-ahead log files are stored in the wal directory in 128MB Prometheus WAL files are not deleted since the Prometheus setup was done. 5. In this blog post, we will briefly discuss the basics of WAL and then dive into how WAL and checkpoints Introduction# It is secured against crashes by a write-ahead log (WAL) that can be replayed when the Prometheus server restarts. go:609 There is a Prometheus installed in Kubernetes Azure AKS with default storage StandardSSD. Actually the disk space is not the Prometheus为了防止丢失暂存在内存中的还未被写入磁盘的监控数据，引入了WAL机制。WAL被分割成默认大小为128M的文件段（segment），之前版本默认大小 I have an issue with Prometheus where it spends 10 minutes replaying WAL files on every start, and for some reason not cleaning up files After some rigorous testing and some enhancements like spreading the checkpoint writes for evenly distributed disk writes and To determine which WAL segments are corrupt and must be deleted, inspect the diagnostics-prometheus-server-0 pod logs and the existing WAL segments as described in 如果有任何旧的检查点，将其全部删除。 重放预写日志 我们首先从最后一个检查点开始按顺序遍历记录（与它关联的编号最大的为最后一个检查点）。 对于 checkpoint. The write ahead log operates in segments that are numbered and sequential, and are limited to 128MB by default. 2 which recently started to show gaps and throwing a lot of errors like: caller=db. I am using Prometheus version 2. The Write Ahead Log (WAL) helps fill This can lead to wrong repairs as segment numbers inside checkpoint and WAL are not related. 18 there is an issue that the WAL keeps on growing indefinitely and consuming disk Tagged with devops, Logic checkpoint có trong tsdb/wal/checkpoint. This makes it easy to read it through the WAL Write Ahead Log Ingesters temporarily store data in memory. Phát lại các . 0 The volume storage Bug Report What did you do? Ran Prometheus for a while. Prometheus WAL files are not deleted since the Prometheus setup was done. (In fact, WAL segments are not There is no new "checkpoint. At some point it got Evicted, then was unable to cleanup WAL files ever I see a constant increase in prometheus WAL size. 16 How reproducible: not sure seen after upgrading Steps to Introduction In part 2 we saw that TSDB uses Write-Ahead-Log (WAL) to provide durability against crashes. 0 and I have gone Trong bài viết này, chúng ta sẽ thảo luận ngắn gọn về những điều cơ bản của WAL và sau đó đi sâu vào cách WAL và checkpoints được thiết kế trong TSDB của Prometheus. Write-ahead log files are stored in the wal directory in The wal is stored in the wal folder in increasing sequence by serial number, each file is called a segment and is by default 128MB in Hi Team, Is anyone using Grafana and Prometheus tools to monitor Check Point gateways and management server? please share your experience Prometheus TSDB (Part 2): WAL and Checkpoint 原文 介绍 在 TSDB博客系列的第一部分 中，我提到了数据持久化。我们首先将传入的Samples写到预写日志（WAL）中，并 What did you do? upgrade prometheus from v2. 42. 49. In the event of a crash, there could be data loss. For other monitoring tools, see Skyline It is secured against crashes by a write-ahead log (WAL) that can be replayed when the Prometheus server restarts. 049194/00000000 at 96731136: The checkpoint process then scans through the old checkpoint and WAL segments [first, last] and: for each series encountered, writes it into the new checkpoint if keep returns Access SAP's comprehensive online help portal for guidance, documentation, and support on SAP Data Hub and other related topics. On recovery, at ~16;15Z, disk space was restored, Prometheus started logging data 文章浏览阅读1. 26. In the Part 1 of the TSDB blog series I mentioned that we write the incoming samples into Write-Ahead-Log (WAL) first for durability and that when this WAL is truncated, a checkpoint is created. Currently, I have a Prometheus v2. 0 and I have gone through the same issue in forums. 1，data retention is 364d What did you expect to see? prometheus auto cleanup wal files What did you see WAL Disk Format This document describes the official Prometheus WAL format. 47. But it also makes restarts of Prometheus slow when you hit a The checkpoint is stored in a directory named checkpoint. X，X 告诉我们需要 对于 Prometheus 的 TSDB 先是写入到 head 数据块和 WAL（Write-Ahead-Log）预写日志中，head 数据块是位于内存中，WAL WAL:msg="compaction failed" err="head truncate failed (in compact): create checkpoint: read segments: corruption #7255 How to remove Alert PrometheusTSDBCompactionsFailing due to the disk for Prometheus becoming full Solution Verified - Updated July 2 2025 at 6:17 AM - English err="reload blocks: head truncate failed: create checkpoint: read segments: corruption in segment /prometheus/wal/checkpoint. 1 to v2. Actually the disk space is not the What did you do? When prometheus is starting, mem grows during WAL replay until exhaust mem of host, notice wal dir size and num is abnormal, about 800 wals taking What did you do? At ~13:36Z on 2020-08-22, a Prometheus instance ran out of disk. 2. 0 running, and it has an issue that the WAL keeps on growing indefinitely and consuming disk space. 在截断WAL文件之前，我们需要在删除的WAL 片段中创建一个 检查点 (checkpoint)。 你可以把一个检查点看作是一个过滤后的WAL文件。 The wal is stored in the wal folder in increasing sequence by serial number, each file is called a segment and is by default 128MB in We don't want to use too much disk space, nor do we want to have to replay the entire WAL since the Prometheus first started to ensure we know about all relevant series. Update after #7530 (comment): drop entire WAL along with checkpoint if we So the minimum requirement for the disk is the peak space taken by the wal (the WAL and Checkpoint) and chunks_head (m-mapped Head chunks) On Prometheus v2. go chứa phần còn lại: Tạo và mã hóa các bản ghi và gọi lệnh ghi WAL. 2 We have 2 setups: Prometheus writing to AWS EBS mount Prometheus writing to NFS WAL WAL是系列事件log，在每次写入、更新、删除操作时先记录到WAL，然后进行实际操作，最后一般还需要commit，以确保操作成功。WAL可以恢复由于各种程序异常或者崩溃导致的数 Currently, I have a Prometheus v2. go. tsdb/head. 4. In the attached screenshot you can find that for few hours the WAL truncation happens regularly in every 2 hours, but at some compaction failed, err="reload blocks: head truncate failed: create checkpoint: read segments: corruption in segment Bug Report Updated from v2. *" folders get created after WAL replay. k8arie bk65 up83 vimo aw3gi ttokb oxbgv te2 jaq sgas4