add changelog

Signed-off-by: Gabriel Fukushima <[email protected]>

CHANGELOG.md

@@ -7,6 +7,21 @@
 ## Unreleased Changes
 
 ### Breaking Changes
+- With the upgrade of the Prometheus Java Metrics library, there are the following changes:
+  - Gauge names are not allowed to end with `total`, therefore metrics as `beacon_proposers_data_total` and `beacon_eth1_current_period_votes_total` are dropping the `_total` suffix
+  - The `_created` timestamps are not returned by default.
+  - Some JVM metrics have changed name to adhere to the OTEL standard (see the table below), [Teku Detailed Dashboard](https://grafana.com/grafana/dashboards/16737-teku-detailed/) is updated to support both names
+
+    | Old Name                        | New Name                        |
+    |---------------------------------|---------------------------------|
+    | jvm_memory_bytes_committed      | jvm_memory_committed_bytes      |
+    | jvm_memory_bytes_init           | jvm_memory_init_bytes           |
+    | jvm_memory_bytes_max            | jvm_memory_max_bytes            |
+    | jvm_memory_bytes_used           | jvm_memory_used_bytes           |
+    | jvm_memory_pool_bytes_committed | jvm_memory_pool_committed_bytes |
+    | jvm_memory_pool_bytes_init      | jvm_memory_pool_init_bytes      |
+    | jvm_memory_pool_bytes_max       | jvm_memory_pool_max_bytes       |
+    | jvm_memory_pool_bytes_used      | jvm_memory_pool_used_bytes      |
 
 ### Additions and Improvements
 - improve block publishing performance, especially relevant with locally produced blocks