Wed, 31 Jan 2024 22:29:42 +0000 en-US hourly 1 https://wordpress.org/?v=6.5.2 https://www.percona.com/blog/wp-content/uploads/2023/02/cropped-percona-favicon-32x32.png 32 32 76301791 https://www.percona.com/blog/wiredtiger-file-forensics-part-3-viewing-all-the-mongodb-data/ https://www.percona.com/blog/wiredtiger-file-forensics-part-3-viewing-all-the-mongodb-data/#respond Tue, 22 Jun 2021 10:47:07 +0000 https://www.percona.com/blog/?p=76750 This article continues on from Part 1: Building “wt” and  “Part 2: wt dump” to show how to extract any of your MongoDB documents directly from WiredTiger’s raw data files. It’ll also show how to take a peek into the index files. Lastly, it’ll show how to also look in the WT transaction log to […]]]> https://www.percona.com/blog/wiredtiger-file-forensics-part-3-viewing-all-the-mongodb-data/feed/ 0 76750 https://www.percona.com/blog/experimental-feature-backupcursorextend-in-percona-server-for-mongodb/ https://www.percona.com/blog/experimental-feature-backupcursorextend-in-percona-server-for-mongodb/#respond Mon, 07 Jun 2021 15:16:28 +0000 https://www.percona.com/blog/?p=76500 Percona Server for MongoDB (PSMDB) has provided a ‘hot’ backup of its underlying data db directory files using WiredTiger library methods since v3.4. When you use the { createBackup: … } command it will copy them to whichever other filesystem directory or object store bucket location you specify.createBackup partially freezes the WiredTiger *.wt Btree files […]]]> https://www.percona.com/blog/experimental-feature-backupcursorextend-in-percona-server-for-mongodb/feed/ 0 76500 https://www.percona.com/blog/wiredtiger-file-forensics-part-2-wt-dump/ Tue, 18 May 2021 14:20:44 +0000 https://www.percona.com/blog/?p=75999 This article contains one normal section – how to print information directly from the raw WiredTiger files using wt dump – followed by really important, otherwise undocumented information about how to get to the MongoDB binary data inside WT tables.See “WiredTiger File Forensics (Part 1: Building “wt”)” for: How to build the “wt” utility command […]]]> 75999 https://www.percona.com/blog/wiredtiger-file-forensics-part-1-building-wt/ Tue, 18 May 2021 13:55:12 +0000 https://www.percona.com/blog/?p=76001 Most of the files in a data directory of a MongoDB server are made by the WiredTiger storage engine. If you want to look at the content inside them you can use the tool “wt” from the WiredTiger library: https://github.com/wiredtiger/wiredtiger/http://source.wiredtiger.com/10.0.0/command_line.htmlInspection of the WiredTiger files is not an essential MongoDB DBA skill – it’s just for […]]]> 76001 https://www.percona.com/blog/percona-backup-for-mongodb-v1-5-released/ Thu, 13 May 2021 12:04:18 +0000 https://www.percona.com/blog/?p=76081 Percona Backup for MongoDB (PBM) has reached a new step with the release of version 1.5.0 today, May 13th, 2021.Azure Blob Storage SupportNow you can use Azure Blob Storage as well as S3-compatible object stores.Configuration example: [crayon-664c892b96e38039473443/]Preference Weight for Backup Source NodesUntil now PBM would use a secondary as a backup source if there is […]]]> 76081 https://www.percona.com/blog/bare-systemd-method-to-create-an-xfs-mount/ Mon, 15 Feb 2021 18:29:11 +0000 https://www.percona.com/blog/?p=74401 For MongoDB data directories only XFS is recommended. The ext4 filesystem isn’t so bad but when there are a very, very high number of random accesses (which WiredTiger can reach) it can hit a bottleneck. To be fair most deployments will never hit this bottleneck, but it does remain an official production recommendation of MongoDB […]]]> 74401 https://www.percona.com/blog/mongodb-4-4-coming-out-soon-what-does-the-code-tell-us/ https://www.percona.com/blog/mongodb-4-4-coming-out-soon-what-does-the-code-tell-us/#comments Thu, 11 Jun 2020 20:27:08 +0000 https://www.percona.com/blog/?p=68974 I’ve been involved with MongoDB for quite a while now. I follow it from the code and I’ve been reviewing the changes in the 4.3 development version, plus the recent 4.4 release candidate versions rc0 – rc7.There are a few thousand github commits, but at the human scale, you’d say 100 ~ 200 things have […]]]> https://www.percona.com/blog/mongodb-4-4-coming-out-soon-what-does-the-code-tell-us/feed/ 1 68974 https://www.percona.com/blog/dealing-with-jumbo-chunks-in-mongodb/ Thu, 11 Jun 2020 14:13:41 +0000 https://www.percona.com/blog/?p=68957 In this blog post, we will discuss how to deal with jumbo chunks in MongoDB.Scenario: You are a MongoDB DBA, and your first task of the day is to remove a shard from your cluster. It sounds scary at first, but you know it is pretty easy. You can do it with a simple command: […]]]> 68957 https://www.percona.com/blog/percona-backup-for-mongodb-v1-2-released/ https://www.percona.com/blog/percona-backup-for-mongodb-v1-2-released/#comments Wed, 27 May 2020 13:22:43 +0000 https://www.percona.com/blog/?p=68595 Percona Backup for MongoDB v1.2 is out! In a nutshell it offers (much) faster compression choices, backup cancellation, and assorted convenience features such as a universal backup deletion command and progress logging.And, for the DBAs out there in the field, we’ve added a whole extra binary (pbm-speed-test) that will give a quick way to investigate […]]]> https://www.percona.com/blog/percona-backup-for-mongodb-v1-2-released/feed/ 2 68595 https://www.percona.com/blog/a-mongodb-prototype-with-new-heterogeneous-memory-storage-engine-hse/ Thu, 14 May 2020 15:03:13 +0000 https://www.percona.com/blog/?p=68298 Introducing a new MongoDB Storage EngineQ. What is the Heterogeneous-memory Storage Engine?A key value store library developed (and open-sourced) by Micron that will work with any normal storage but works especially well with emerging SSDs or NVDIMMS (or other Storage Class Memory) that have faster even NVM media in them (Bleeding-edge NAND, or Optane / […]]]> 68298 https://www.percona.com/blog/tactics-to-scale-down-your-mongodb-deployment/ Mon, 20 Apr 2020 06:01:26 +0000 https://www.percona.com/blog/?p=67314 “Get big fast” was a mantra in the second eCommerce boom. MongoDB’s success during its startup years was due in large part to being the best database to support that.But maybe, after your growth years, the data’s rent bill has become a little high? Big data was nice, but you absorbed a lot of it, […]]]> 67314 https://www.percona.com/blog/dba-concerns-about-next-gen-non-volatile-memory-storage-products/ Wed, 11 Mar 2020 16:24:03 +0000 https://www.percona.com/blog/?p=65794 Abstract: Storage engine algorithmic gains have mostly settled and Moore’s law for CPU speed is bottoming out, but database performance still stands to increase ~10x thanks to continuing NAND Flash improvement, Optane, Flash-idiomatic SSD drives (e.g. OpenChannel, Zoned Namespaces), KeyValue SSD, etc. The downside is each storage engine revolution historically has broken encapsulation/reuse and required […]]]> 65794 https://www.percona.com/blog/mongodb-compatibility-in-aws-documentdb/ https://www.percona.com/blog/mongodb-compatibility-in-aws-documentdb/#comments Fri, 20 Dec 2019 15:07:37 +0000 https://www.percona.com/blog/?p=64041 Recently I noticed the site www.isdocumentdbreallymongodb.com. The page headline is:In short, MongoDB is saying that AWS DocumentDB, one of its DB-as-a-service competitors, is not even half-compatible for existing users of its DBAAS MongoDB Atlas.I think the claim above is terrible, for two reasons: Innumeracy is a sin. Feature compatibility is not a percentage, it is […]]]> https://www.percona.com/blog/mongodb-compatibility-in-aws-documentdb/feed/ 2 64041 https://www.percona.com/blog/dont-use-mongodb-profiling-level-1/ https://www.percona.com/blog/dont-use-mongodb-profiling-level-1/#comments Fri, 15 Nov 2019 14:33:10 +0000 https://www.percona.com/blog/?p=63376 TLDR: It is not profile level 1 that is the problem; it’s a gotcha with the optional ‘slowms’ argument that causes users to accidentally set verbose logging and fill their disk with log files.In MongoDB, there are two ways to see, with individual detail, which operations were executed and how long they took. Profiling. Saves […]]]> https://www.percona.com/blog/dont-use-mongodb-profiling-level-1/feed/ 5 63376 https://www.percona.com/blog/long-awaited-mongodb-4-2-ga-has-landed/ https://www.percona.com/blog/long-awaited-mongodb-4-2-ga-has-landed/#comments Fri, 16 Aug 2019 16:24:05 +0000 https://www.percona.com/blog/?p=61575 Editor’s Note: The first version of this post contained a section criticizing what appeared to be a major regression concerning dropDatabase and movePrimary commands. It was found out that it was merely a documentation error in the MongoDB 4.2 release notes, which is now fixed: https://jira.mongodb.org/browse/DOCS-12474. The “(In)Stability” section is now removed.At Percona we’ve been […]]]> https://www.percona.com/blog/long-awaited-mongodb-4-2-ga-has-landed/feed/ 6 61575 https://www.percona.com/blog/network-transport-encryption-for-mongodb/ Tue, 30 Jul 2019 15:11:52 +0000 https://www.percona.com/blog/?p=59562 Why do I need Network encryption?In our previous blog post MongoDB Security vs. Five ‘Bad Guys’ there’s an overview of five main areas of security functions.Let’s say you’ve enabled #1 and #2 (Authentication, Authorization) and #4 (Storage encryption a.k.a. encryption-at-rest and Auditing) mentioned in the previous blog post. Only authenticated users will be connecting, and […]]]> 59562 https://www.percona.com/blog/mongodb-security-vs-five-bad-guys/ Fri, 12 Jul 2019 13:51:43 +0000 https://www.percona.com/blog/?p=58905 Most any commercially mature DBMS provides the following five ways to secure the data you keep inside it: Authentication of user connections (== Identity) Authorization (== DB command permissions) (a.k.a. Role-based access control) Network Encryption (a.k.a. Transport encryption) Storage Encryption (a.k.a. Encryption-at-rest) Auditing (MongoDB Enterprise or Percona Server for MongoDB only) MongoDB is no exception. […]]]> 58905 https://www.percona.com/blog/mongodb-disaster-snapshot-restore-and-point-in-time-replay/ https://www.percona.com/blog/mongodb-disaster-snapshot-restore-and-point-in-time-replay/#comments Fri, 05 Jul 2019 15:02:35 +0000 https://www.percona.com/blog/?p=58392 Mistakes can happen. If only we could go back in time to the very second before that mistake was made.Act 1: The DisasterPlain text version for those who cannot run the asciicast above: [crayon-664c892b9ad6c339352807/]Act 2: Time travel with a Snapshot restore + Oplog replayPlain text version for those who cannot run the asciicast above: [crayon-664c892b9ad72071329876/] […]]]> https://www.percona.com/blog/mongodb-disaster-snapshot-restore-and-point-in-time-replay/feed/ 1 58392 https://www.percona.com/blog/diving-into-the-mongodb-4-2-release-small-print/ Tue, 25 Jun 2019 13:51:48 +0000 https://www.percona.com/blog/?p=58079 In my previous blog post “Percona’s View on MongoDB’s 4.2 Release – The Good, the Bad, and the Ugly…” I discussed the release of transaction support in sharded clusters, field-level encryption, search-engine integration, and the new update command syntaxes.Those are all very important, but to me making MongoDB easier to use and removing technical debt […]]]> 58079 https://www.percona.com/blog/view-on-mongodb-4-2-release-the-good-the-bad-and-the-ugly/ Fri, 21 Jun 2019 14:44:38 +0000 https://www.percona.com/blog/?p=58077 This is part 1 of 2: The keynote-marketed features. Percona’s MongoDB Tech Lead Akira Kurogane takes a look at MongoDB’s 4.2 release.Initial thoughts? Some great! Some not so compelling.Distributed TransactionsIncluding distributed transactions is a great accomplishment, making MongoDB the only popular NoSQL distributed database to plug the gap with this fundamental feature, previously only available in RDBMS. […]]]> 58077