fix(cluster): Remove per-call srand in valkey-cli (9.1 backport)#3668
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Backport of valkey-io#3586 to 9.1 branch. clusterManagerNodePrimaryRandom() called srand(time(NULL)) on every invocation, then immediately rand() % primary_count. When called in a tight loop for uncovered slots, all calls within the same wall-clock second produce the identical seed, causing every uncovered slot to be assigned to the same primary node. Remove all per-call srand() invocations and consolidate into a single srand(time(NULL) ^ getpid()) at the start of main(). This allows rand() to advance its state across calls, distributing uncovered slots randomly across available primaries. (cherry picked from commit 7e2a2f7) Signed-off-by: Ran Shidlansik <ranshid@amazon.com>
enjoy-binbin
approved these changes
May 12, 2026
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## 9.1 #3668 +/- ##
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- Coverage 76.40% 76.39% -0.01%
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Files 161 161
Lines 80710 80707 -3
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- Hits 61663 61658 -5
- Misses 19047 19049 +2
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zuiderkwast
approved these changes
May 12, 2026
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Backport of #3586 to the 9.1 branch.
Problem
clusterManagerNodePrimaryRandom()calledsrand(time(NULL))on every invocation, then immediatelyrand() % primary_count. When called in a tight loop for uncovered slots, all calls within the same wall-clock second produce the identical seed, causing every uncovered slot to be assigned to the same primary node.The same issue existed in
clusterManagerOptimizeAntiAffinity,pipeMode, andLRUTestMode.Solution
Remove all per-call
srand()invocations and consolidate into a singlesrand(time(NULL) ^ getpid())at the start ofmain(). This allowsrand()to advance its state across calls, distributing uncovered slots randomly across available primaries.(cherry picked from commit 7e2a2f7)