--- title: The Good, the Bad, and the Leaky: jemalloc, bumpalo, and... description: A deep dive into a memory leak investigation in Meilisearch, tracing through multiple suspects: a bumpalo allocator misuse (storing std::Vec inside... canonical: https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in meilisearch | daily.dev og:description: A deep dive into a memory leak investigation in Meilisearch, tracing through multiple suspects: a bumpalo allocator misuse (storing std::Vec inside... og:url: https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf og:image: https://api.daily.dev/og/posts/eiwrMznlf.png og:image:alt: The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in meilisearch og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in meilisearch **[Lobsters](https://daily.dev/sources/lobsters)** · 9 min read · 0 upvotes · 0 comments ## Summary A deep dive into a memory leak investigation in Meilisearch, tracing through multiple suspects: a bumpalo allocator misuse (storing std::Vec inside bumpalo::Vec, preventing drop glue from running), and ultimately a more significant issue with mimalloc v2 failing to cooperate with LMDB's system allocator. The root cause was that LMDB and Meilisearch were using different allocators, causing pages to be allocated and deallocated without being reusable. Switching to a unified allocator (jemalloc or mimalloc v3) resolved the RSS growth. Mimalloc v3 proved especially effective due to improved thread memory sharing and lower memory usage for large workloads, yielding ~13% performance gains in benchmarks. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in Meilisearch](https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-tzy8no3lm) · Meilisearch · 1 upvotes · 0 comments --- Tags: [#rust](https://daily.dev/tags/rust), [#meilisearch](https://daily.dev/tags/meilisearch) [View this post on daily.dev](https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in meilisearch","url":"https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf"},"datePublished":"2026-03-21T15:43:10.080Z","dateModified":"2026-03-21T15:43:35.664Z","description":"A deep dive into a memory leak investigation in Meilisearch, tracing through multiple suspects: a bumpalo allocator misuse (storing std::Vec inside...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c8d36d195ddbd38f023dff86fb2f83f4?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c8d36d195ddbd38f023dff86fb2f83f4?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Lobsters","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Lobsters","logo":"https://media.daily.dev/image/upload/s--tl8v_Fku--/f_auto,t_logo/v1698841318/logos/lobste.jpg","url":"https://daily.dev/sources/lobsters"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/the-good-the-bad-and-the-leaky-jemalloc-bumpalo-and-mimalloc-in-meilisearch-eiwrmznlf","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"rust,meilisearch","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Lobsters","item":"https://daily.dev/sources/lobsters"},{"@type":"ListItem","position":3,"name":"The Good, the Bad, and the Leaky: jemalloc, bumpalo, and mimalloc in meilisearch"}]} ```