# 9. JFR redaction (JEP 536) and the Vector API (JEP 537)

Prev: [8. PEM](08-pem-api.md) · Next: [10. Other 27 changes](10-other-27-changes.md)

## JFR redacts secrets in the recording by default

A JFR file records the JVM's command-line arguments, system properties and environment variables. Those routinely hold passwords and tokens, and recordings get attached to tickets.
[`scripts/jfr-redaction.sh`](../scripts/jfr-redaction.sh) starts an [`Idle`](../jep-tour/src/Idle.java) process with `-Dapi.token=abc123 -Dregion=ap-south-1 ... --password=hunter2 --user=ankur`
and `DB_PASSWORD=hunter2` in the environment, then prints what reached the file ([40](output/40-jfr-redaction.txt)):

| Configuration | `-Dapi.token` | `--password` | `DB_PASSWORD` | `region` |
|---|---|---|---|---|
| JDK 26 | abc123 | hunter2 | hunter2 | ap-south-1 |
| JDK 27 default | `[REDACTED]` | `[REDACTED]` | `[REDACTED]` | ap-south-1 |
| 27, `redact-argument=--user*,redact-key=region` | abc123 (exposed) | hunter2 (exposed) | hunter2 (exposed) | `[REDACTED]` |
| 27, `redact-argument=+--user*,redact-key=+region` | `[REDACTED]` | `[REDACTED]` | `[REDACTED]` | `[REDACTED]` |
| 27, `redact-argument=none,redact-key=none` | abc123 | hunter2 | hunter2 | ap-south-1 |

**The trap in row 3:** a list you supply *replaces* the built-in patterns. Without the `+` prefix you have silently turned the defaults off for everything you did not list.

## The Vector API is still incubating

[`VectorDemo`](../jep-tour/src/VectorDemo.java) ([25](output/25-vector.txt)) computes a dot product with and without `jdk.incubator.vector` and asserts they agree within 0.1%.
The same class file runs on 26 (eleventh incubator, JEP 529) and 27 (twelfth, JEP 537): the only public API change between them is that `VectorOperators` changed from `abstract` to `final`
([50](output/50-vector-api-surface.txt)). The preferred species is machine dependent (`S_512_BIT`, 16 float lanes, on the machine that wrote the transcript).
For the API itself see the ankurm.com guide: <https://ankurm.com/java-vector-api-jep-537-simd-guide/>.

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