Add blog post for CDC

Author: tyler-french

website/blog/content-defined-chunking.md

@@ -42,6 +42,8 @@ Once you’ve added these flags, you’ll see a line like `Streaming build resul
   - This flag can reduce uploads by not uploading locally executed action outputs to the remote cache. This will reduce the cache hit rate for future runs, but can be desirable if upload speed is constrained (due to a poor network connection, for example).
 - `--remote_cache_compression`
   - This flag can improve remote cache throughput by compressing cache blobs.
+- <code className="flag">--experimental_remote_cache_chunking</code>
+  - This flag can improve remote cache throughput for large outputs by uploading and downloading them in content-defined chunks, when supported by the remote cache. This is available in Bazel 8.7 and 9.1+.
 - `--digest_function=BLAKE3`
   - This flag can improve the performance of digest calculation of large files by using a faster hashing algorithm. This is available for Bazel 6.4+.
 - `--jobs`

website/blog/why-was-my-bazel-build-so-slow.md

@@ -7,19 +7,18 @@ tags: [bazel, featured]
 
 We're excited to announce end-to-end content-defined chunking (CDC) support for Bazel remote caching in BuildBuddy.
 
-With Bazel 9.1's new `--experimental_remote_cache_chunking` support, large outputs like linker artifacts can be uploaded and downloaded in content-defined chunks instead of as monolithic blobs. That lets BuildBuddy deduplicate similar artifacts across builds, reducing upload bandwidth and storage usage. In one benchmark on the BuildBuddy repo, this showed roughly 40% less uploaded data and a roughly 40% smaller disk cache. Breaking large blobs into smaller reusable pieces also means fewer long-running RPCs and more granular retries.
+With Bazel 9.1's new <code className="flag">--experimental_remote_cache_chunking</code> support, large outputs like linker artifacts can be uploaded and downloaded in content-defined chunks instead of as monolithic blobs. That lets BuildBuddy deduplicate similar artifacts across builds, reducing upload bandwidth and storage usage. In one benchmark on the BuildBuddy repo, this showed roughly 40% less uploaded data and a roughly 40% smaller disk cache. Breaking large blobs into smaller reusable pieces also means fewer long-running RPCs and more granular retries.
 
-To enable it, add these flags to your `.bazelrc`:
+To enable it, add this flag to your `.bazelrc`:
 
 ```text
 common --experimental_remote_cache_chunking
-common --remote_header=x-buildbuddy-cdc-enabled=true
 ```
 
 To see the download-side savings, you should also set `--disk_cache`, since the downloaded chunks need to be stored somewhere in order to be reused locally. We also recommend setting <code className="flag">--experimental_disk_cache_gc_max_age</code> to a value below your remote cache TTL—for example, `3h`, or `1d` if your remote TTL is longer.
 
-Bazel 9.1 is required today, and this support will also be backported to Bazel 8.7.
+Bazel 9.1 and 8.7 support this flag.
 
 For more background, see [bazelbuild/bazel#28437](https://github.com/bazelbuild/bazel/pull/28437).
 
-We'll share a longer blog post soon with more details on the technical journey behind this work.
+For a deeper dive, see [No More Large Outputs: Introducing Remote Cache CDC](/blog/content-defined-chunking).