ddtrace/tracer: better trace and span ID randomness #1472
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knusbaum
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Sep 20, 2022
knusbaum
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This resolves an issue that could cause collisions due to
randomonly using a 32 bit seed. Even though we're generating a nice cryptographically secure 64 bit seed it actually is only using 32 bits. This means that if a customer is running a large number (e.g. > 30k) of go service instances that generate spans, there is a possibility for a traceid / spanID collision.To resolve this we XOR the generated 64 bit number with the span start time, this keeps the random numbers evenly distributed but reduces the likelihood of a collision should two instances of a service get the same random seed.