{"id":"e12d0dc92cd7697e","repo":"redis/node-redis","slug":"cannot-split-label-invalid-keystep-keystep","errorCode":null,"errorMessage":"Cannot split ${label}: invalid keystep ${keyStep}","messagePattern":"Cannot split (.+?): invalid keystep (.+?)","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/client/lib/cluster/request-response-policies/multi-shard-splitter.ts","lineNumber":102,"sourceCode":"      keyStep = findKeys.keyStep;\n      keyNumIdx = start + findKeys.keyNumIdx;\n      keyRegionStart = start + findKeys.firstKey;\n      if (keyNumIdx >= keyRegionStart) {\n        throw new Error(`Cannot split ${label}: numkeys argument inside the key region`);\n      }\n      const numKeys = parsePositiveInteger(args[keyNumIdx]);\n      if (numKeys === undefined) {\n        throw new Error(`Cannot split ${label}: malformed numkeys argument '${args[keyNumIdx]}'`);\n      }\n      keyRegionEnd = keyRegionStart + numKeys * keyStep;\n      break;\n    }\n    default:\n      throw new Error(`Cannot split ${label}: unsupported find_keys type '${findKeys.type}'`);\n  }\n\n  if (keyStep < 1) {\n    throw new Error(`Cannot split ${label}: invalid keystep ${keyStep}`);\n  }\n  if (keyRegionStart < 1 || keyRegionEnd > args.length) {\n    throw new Error(`Cannot split ${label}: key region overruns the arguments`);\n  }\n  const regionLength = keyRegionEnd - keyRegionStart;\n  if (regionLength <= 0 || regionLength % keyStep !== 0) {\n    throw new Error(`Cannot split ${label}: key region does not align with keystep ${keyStep}`);\n  }\n\n  const groupCount = regionLength / keyStep;\n  const slotGroups = new Map<number, Array<number>>();\n  for (let group = 0; group < groupCount; group++) {\n    const slot = calculateSlot(args[keyRegionStart + group * keyStep]);\n    const groups = slotGroups.get(slot);\n    if (groups) {\n      groups.push(group);\n    } else {\n      slotGroups.set(slot, [group]);","sourceCodeStart":84,"sourceCodeEnd":120,"githubUrl":"https://github.com/redis/node-redis/blob/bb5beb56578573910e2ee8f39681edc214c41398/packages/client/lib/cluster/request-response-policies/multi-shard-splitter.ts#L84-L120","documentation":"splitMultiShardCommand requires keyStep >= 1 — keyStep is the stride between successive key groups (1 for DEL/MGET, 2 for MSET where each key is followed by its value). A keyStep < 1 is structurally invalid (zero or negative stride) and would produce infinite/overlapping groups, so the splitter refuses. This is a spec invariant; no real command declares keyStep < 1.","triggerScenarios":"A command tagged multi_shard whose spec reports keyStep < 1. Reachable only via malformed metadata or a future spec; not user-argument-triggered.","commonSituations":"A metadata corruption/regeneration producing a zero/negative keyStep; an exotic future spec.","solutions":["Verify the command's keyStep in metadata is >= 1.","Re-run metadata generation against a healthy Redis node.","Re-tag the command to default-keyed routing if the spec is unusable."],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":null,"typeGuard":"function isValidKeyStep(spec: unknown): boolean {\n  return typeof spec === 'object' && spec !== null && typeof (spec as { keyStep?: number }).keyStep === 'number' && (spec as { keyStep?: number }).keyStep! >= 1;\n}","tryCatchPattern":"try {\n  await cluster.del('k1', 'k2');\n} catch (e) {\n  if (/invalid keystep/.test(e.message)) {\n    // metadata reports keyStep < 1 — regenerate or override\n  } else throw e;\n}","preventionTips":["Verify the command's keyStep in metadata is >= 1.","Re-run metadata generation against a healthy Redis node.","Re-tag commands with unusable specs to default-keyed routing."],"tags":["cluster","multi-shard","metadata","keyspec","splitter"],"analyzedSha":"bb5beb56578573910e2ee8f39681edc214c41398","analyzedAt":"2026-08-03T19:09:15.686Z","schemaVersion":2}