--- title: Consistent Hashing and Its Implementation From the First... description: A breakdown of consistent hashing explaining it's just a simple lookup algorithm, not a service, used to determine data or request ownership across a cluster... canonical: https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Consistent Hashing and Its Implementation From the First Principles | daily.dev og:description: A breakdown of consistent hashing explaining it's just a simple lookup algorithm, not a service, used to determine data or request ownership across a cluster... og:url: https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm og:image: https://api.daily.dev/og/posts/X5btHfPdM.png og:image:alt: Consistent Hashing and Its Implementation From the First Principles 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. # Consistent Hashing and Its Implementation From the First Principles **[Asli Engineering by Arpit Bhayani](https://daily.dev/sources/asli-engineering)** · 13 min read · 0 upvotes · 0 comments ## Summary A breakdown of consistent hashing explaining it's just a simple lookup algorithm, not a service, used to determine data or request ownership across a cluster of nodes. The talk contrasts it with classic hash-based (mod n) ownership, which causes massive reshuffling when nodes are added or removed, versus consistent hashing's ring-based approach that minimizes ownership changes. Implementation is shown to be a simple sorted array lookup (find the first node greater than a given key's hash), rather than requiring a linked list or ring data structure. It also warns against treating consistent hashing as a magic bullet, noting it doesn't handle actual data migration and may not fit use cases needing fine-grained control. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do you implement consistent hashing without using a huge array or linked list for the whole hash ring? Only store the nodes themselves in a small array, ordered by their position on the hash ring, rather than allocating an array sized to the full hash range (like 2^128 or 2^256). Given a key's hash value, perform a lookup to find the first node in the array whose position is greater than that hash value; that node owns the key. This can be a simple linear scan for small clusters or a binary search, tree, or skip list for larger ones. _daily.dev surfaces practical breakdowns like this for engineers implementing scalable data ownership schemes._ ### What problem does consistent hashing solve compared to plain hash-based ownership using mod n? Consistent hashing solves the ownership-change problem that occurs when a cluster's node count changes. With plain hash(key) mod n ownership, changing n reshuffles almost all keys to different nodes, since the modulus itself changes; in one example, only 2 out of 12 nodes kept their assignments after a change. Consistent hashing places nodes on a ring so adding or removing a node only reassigns the keys in the affected range, leaving the rest untouched. _Engineers weighing sharding strategies can track these tradeoffs and implementation nuances on daily.dev._ ## Similar posts on daily.dev - [Consistent Hashing in a Nutshell](https://daily.dev/posts/consistent-hashing-in-a-nutshell-pd2r4z3hs) · System Design Codex · 2 upvotes · 0 comments - [Eli Bendersky's website](https://daily.dev/posts/eli-bendersky-s-website-05uihsz00) · Eli Bendersky · 2 upvotes · 0 comments --- Tags: [#career](https://daily.dev/tags/career), [#distributed-systems](https://daily.dev/tags/distributed-systems), [#data-structures](https://daily.dev/tags/data-structures) [View this post on daily.dev](https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm) ```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":"Consistent Hashing and Its Implementation From the First Principles","url":"https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm"},"datePublished":"2026-09-01T13:09:35.850Z","dateModified":"2026-09-01T13:09:58.694Z","description":"A breakdown of consistent hashing explaining it's just a simple lookup algorithm, not a service, used to determine data or request ownership across a cluster...","image":"https://i.ytimg.com/vi/Jvimt56KPnk/sddefault.jpg","thumbnailUrl":"https://i.ytimg.com/vi/Jvimt56KPnk/sddefault.jpg","isAccessibleForFree":true,"articleSection":"Asli Engineering by Arpit Bhayani","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":"Asli Engineering by Arpit Bhayani","logo":"https://media.daily.dev/image/upload/s--qezTGRtV--/f_auto,q_auto/v1780213733/logos/asli-engineering?_a=BAMAMiWQ0","url":"https://daily.dev/sources/asli-engineering"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"career,distributed-systems,data-structures","timeRequired":"PT13M","video":{"@type":"VideoObject","name":"Consistent Hashing and Its Implementation From the First Principles","description":"A breakdown of consistent hashing explaining it's just a simple lookup algorithm, not a service, used to determine data or request ownership across a cluster...","thumbnailUrl":"https://i.ytimg.com/vi/Jvimt56KPnk/sddefault.jpg","uploadDate":"2026-09-01T13:09:35.850Z","duration":"PT13M","url":"https://api.daily.dev/r/X5btHfPdM","embedUrl":"https://www.youtube.com/embed/Jvimt56KPnk"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Asli Engineering by Arpit Bhayani","item":"https://daily.dev/sources/asli-engineering"},{"@type":"ListItem","position":3,"name":"Consistent Hashing and Its Implementation From the First Principles"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/consistent-hashing-and-its-implementation-from-the-first-principles-x5bthfpdm#faq","mainEntity":[{"@type":"Question","name":"How do you implement consistent hashing without using a huge array or linked list for the whole hash ring?","acceptedAnswer":{"@type":"Answer","text":"Only store the nodes themselves in a small array, ordered by their position on the hash ring, rather than allocating an array sized to the full hash range (like 2^128 or 2^256). Given a key's hash value, perform a lookup to find the first node in the array whose position is greater than that hash value; that node owns the key. This can be a simple linear scan for small clusters or a binary search, tree, or skip list for larger ones. daily.dev surfaces practical breakdowns like this for engineers implementing scalable data ownership schemes."}},{"@type":"Question","name":"What problem does consistent hashing solve compared to plain hash-based ownership using mod n?","acceptedAnswer":{"@type":"Answer","text":"Consistent hashing solves the ownership-change problem that occurs when a cluster's node count changes. With plain hash(key) mod n ownership, changing n reshuffles almost all keys to different nodes, since the modulus itself changes; in one example, only 2 out of 12 nodes kept their assignments after a change. Consistent hashing places nodes on a ring so adding or removing a node only reassigns the keys in the affected range, leaving the rest untouched. Engineers weighing sharding strategies can track these tradeoffs and implementation nuances on daily.dev."}}]} ```