René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Userdispersing algorithm does not consider VMs in starting state","articleBody":"### problem\n\nI tried to use userdispersing algorithm for volumes and VMs, still I've got numerous VMs starting on the same host. See https://github.com/apache/cloudstack/discussions/11412\nIn the end it was confirmed that algorithm considers just running VMs.\nAs VM start takes time, and VMs are started in packs (Jenkins jcloud plugin), all VMs are placed to the same host. Finally I had to switch to random algo that do dispersing a lot better (though not ideal)\nI believe  that as soon as VM is assigned for start on a host (still in Starting state), it should be already considered by userdispersing algorithm.\n\n### versions\n\nCloudStack 4.21.0.0, though I had the same issue with 4.20\nKVM\nlocal fat volumes\n\n### The steps to reproduce the bug\n\n1. Confiugre CS to use userdispersing algorithm (volumes and VMs)\n2. Start several VMs via api without waiting for response that VM was started, e.g.\n```\nfor i in {01..10}; do cloudstack deployVirtualMachine serviceofferingid=XXX templateid=YYY zoneid=ZZZ name=test-${i} \u0026 done\n```\nin my env all VMs start on the same host, even if I add some delay to the loop, unless the delay is enough to fully start VM\n\n### What to do about it?\n\nAlgorithm should query both Running and Starting VMs and use that data to decide the next VM placement","author":{"url":"https://github.com/akrasnov-drv","@type":"Person","name":"akrasnov-drv"},"datePublished":"2025-09-10T15:16:05.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/11606/cloudstack/issues/11606"}