[{"data":1,"prerenderedAt":126},["ShallowReactive",2],{"term-q\u002Fquorum":3,"related-q\u002Fquorum":109},{"id":4,"title":5,"acronym":6,"body":7,"category":89,"description":90,"difficulty":91,"extension":92,"letter":93,"meta":94,"navigation":95,"path":96,"related":97,"seo":103,"sitemap":104,"stem":107,"subcategory":6,"__hash__":108},"terms\u002Fterms\u002Fq\u002Fquorum.md","Quorum",null,{"type":8,"value":9,"toc":83},"minimark",[10,15,19,23,26,30,72,76,79],[11,12,14],"h2",{"id":13},"eli5-the-vibe-check","ELI5 - The Vibe Check",[16,17,18],"p",{},"A quorum is the minimum number of nodes that must agree before a distributed system trusts a decision, whether that's electing a leader or confirming a write actually stuck. Requiring a majority, rather than just one node, means the system can survive some nodes going dark without losing correctness, and it mathematically guarantees that two conflicting decisions can never both get enough votes at the same time.",[11,20,22],{"id":21},"real-talk","Real Talk",[16,24,25],{},"A quorum is the minimum number of nodes required to agree for an operation, such as a leader election or a read or write, to be considered valid, typically set as a strict majority of the cluster to guarantee that any two quorums overlap by at least one node. In quorum-based replication (the Dynamo-style model), read quorum R and write quorum W are tuned so that R plus W exceeds the total replica count N, ensuring every read overlaps with the most recent write, trading off consistency, availability, and latency.",[11,27,29],{"id":28},"show-me-the-code","Show Me The Code",[31,32,37],"pre",{"className":33,"code":34,"language":35,"meta":36,"style":36},"language-python shiki shiki-themes material-theme-lighter material-theme material-theme-palenight","# Dynamo-style quorum config: N=5 replicas\n# R + W > N guarantees read\u002Fwrite overlap\nwrite_quorum = 3   # W\nread_quorum = 3    # R\n# 3 + 3 > 5, so every read sees the latest write\n","python","",[38,39,40,48,54,60,66],"code",{"__ignoreMap":36},[41,42,45],"span",{"class":43,"line":44},"line",1,[41,46,47],{},"# Dynamo-style quorum config: N=5 replicas\n",[41,49,51],{"class":43,"line":50},2,[41,52,53],{},"# R + W > N guarantees read\u002Fwrite overlap\n",[41,55,57],{"class":43,"line":56},3,[41,58,59],{},"write_quorum = 3   # W\n",[41,61,63],{"class":43,"line":62},4,[41,64,65],{},"read_quorum = 3    # R\n",[41,67,69],{"class":43,"line":68},5,[41,70,71],{},"# 3 + 3 > 5, so every read sees the latest write\n",[11,73,75],{"id":74},"when-youll-hear-this","When You'll Hear This",[16,77,78],{},"\"We can only lose two nodes before we drop below quorum and stop accepting writes.\" \u002F \"Tune R and W so reads always overlap with the latest write.\"",[80,81,82],"style",{},"html .light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html.light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html.dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}",{"title":36,"searchDepth":50,"depth":50,"links":84},[85,86,87,88],{"id":13,"depth":50,"text":14},{"id":21,"depth":50,"text":22},{"id":28,"depth":50,"text":29},{"id":74,"depth":50,"text":75},"architecture","A quorum is the minimum number of nodes that must agree before a distributed system trusts a decision, whether that's electing a leader or confirming a wri...","advanced","md","q",{},true,"\u002Fterms\u002Fq\u002Fquorum",[98,99,100,101,102],"Consensus Algorithm","Split Brain","Raft","Distributed Lease","Multi-Region Active-Active",{"title":5,"description":90},{"changefreq":105,"priority":106},"weekly",0.7,"terms\u002Fq\u002Fquorum","1p885-diJwddP98DxtJCvqO6wbVpcIoLBzSwzgOYS4g",[110,114,117,120,123],{"title":98,"path":111,"acronym":6,"category":112,"difficulty":91,"description":113},"\u002Fterms\u002Fc\u002Fconsensus-algorithm","database","A consensus algorithm is how a group of servers democratically agree on something even when some of them are flaky or unreachable.",{"title":101,"path":115,"acronym":6,"category":89,"difficulty":91,"description":116},"\u002Fterms\u002Fd\u002Fdistributed-lease","A distributed lease is a time-limited 'I've got this' claim that one node takes out on a resource or a role, like being the leader, so everyone else knows...",{"title":102,"path":118,"acronym":6,"category":89,"difficulty":91,"description":119},"\u002Fterms\u002Fm\u002Fmulti-region-active-active","Active-passive means you've got a backup region sitting idle, ready to take over if the primary region dies, kind of like a spare tire in your trunk.",{"title":100,"path":121,"acronym":6,"category":112,"difficulty":91,"description":122},"\u002Fterms\u002Fr\u002Fraft","Raft is a consensus algorithm designed to be understandable, unlike its predecessor Paxos which requires a PhD to read.",{"title":99,"path":124,"acronym":6,"category":89,"difficulty":91,"description":125},"\u002Fterms\u002Fs\u002Fsplit-brain","Split brain is when a network hiccup cuts a cluster of servers in half, and both halves, unable to talk to each other, each decide they're the boss and kee...",1792528112427]