Reduce overhead of creating / parsing / serializing trace IDs. #212
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willarmiros
approved these changes
Sep 9, 2020
| @@ -42,6 +48,32 @@ public static StringBuilder stringBuilder() { | |||
| return buffer; | |||
| } | |||
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| /** | |||
| * A {@link ThreadLocal} {@code char[]} of length {@code length}. The array is not zeroed in any way - every character of | |||
| * a resulting {@link String} must be set explicitly. The array returned my be longer than {@code length} - always explicitly | |||
| import org.junit.jupiter.api.RepeatedTest; | ||
| import org.junit.jupiter.api.Test; | ||
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| class TraceIDTest { |
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Thanks so much for adding these!! Probably should've been here from day 1 :/
anuraaga
commented
Sep 10, 2020
aws-xray-recorder-sdk-core/src/main/java/com/amazonaws/xray/internal/RecyclableBuffers.java
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…ternal/RecyclableBuffers.java
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Description of changes:
TraceIDcurrently stores its components as a long for epoch andBigIntegerfor random number. However, these numeric representations provide mostly no value as in almost all usage a trace ID is just an opaque string (propagation, emitting). So we can reduce the overhead of parsing the ID by storing fields as hex strings themselves, the same format we use in propagating. We also reduce overhead in serialization by only generating the String once, instead of multiple times (2 times without log propagation, potentially hundreds of times with log propagation in a reactive server, ignoring any other debug logging that may happen).As a result, creation is a tiny bit slower due to the extra work of converting long to string, and biginteger also converts byte array to int array which is a big faster than byte array to hex string. But this is near 0 while we get 3-4x savings in the other operations.
Most conversion code is adapted from OTel.
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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.