This may be a breaking change for users who rely on particular kopia metrics (unlikely):
- introduced blob-level metrics:
* `kopia_blob_download_full_blob_bytes_total`
* `kopia_blob_download_partial_blob_bytes_total`
* `kopia_blob_upload_bytes_total`
* `kopia_blob_storage_latency_ms` - per-method latency distribution
* `kopia_blob_errors_total` - per-method error counter
- updated cache metrics to indicate particular cache
* `kopia_cache_hit_bytes_total{cache="CACHE_TYPE"}`
* `kopia_cache_hit_total{cache="CACHE_TYPE"}`
* `kopia_cache_malformed_total{cache="CACHE_TYPE"}`
* `kopia_cache_miss_total{cache="CACHE_TYPE"}`
* `kopia_cache_miss_errors_total{cache="CACHE_TYPE"}`
* `kopia_cache_miss_bytes_total{cache="CACHE_TYPE"}`
* `kopia_cache_store_errors_total{cache="CACHE_TYPE"}`
where `CACHE_TYPE` is one of `contents`, `metadata` or `index-blobs`
- reorganized and unified content-level metrics:
* `kopia_content_write_bytes_total`
* `kopia_content_write_duration_nanos_total`
* `kopia_content_compression_attempted_bytes_total`
* `kopia_content_compression_attempted_duration_nanos_total`
* `kopia_content_compression_savings_bytes_total`
* `kopia_content_compressible_bytes_total`
* `kopia_content_non_compressible_bytes_total`
* `kopia_content_after_compression_bytes_total`
* `kopia_content_decompressed_bytes_total`
* `kopia_content_decompressed_duration_nanos_total`
* `kopia_content_encrypted_bytes_total`
* `kopia_content_encrypted_duration_nanos_total`
* `kopia_content_hashed_bytes_total`
* `kopia_content_hashed_duration_nanos_total`
* `kopia_content_deduplicated_bytes_total`
* `kopia_content_read_bytes_total`
* `kopia_content_read_duration_nanos_total`
* `kopia_content_decrypted_bytes_total`
* `kopia_content_decrypted_duration_nanos_total`
* `kopia_content_uploaded_bytes_total`
Also introduced `internal/metrics` framework which constructs Prometheus metrics in a uniform way and will allow us to include some of these metrics in telemetry report in future PRs.
New flag `--enable-jaeger-collector` and the corresponding
`KOPIA_ENABLE_JAEGER_COLLECTOR` environment variable enables Jaeger
exporter, which by default sends OTEL traces to Jaeger collector on
http://localhost:14268/api/traces
To change this, use environment variables:
* `OTEL_EXPORTER_JAEGER_ENDPOINT`
* `OTEL_EXPORTER_JAEGER_USER`
* `OTEL_EXPORTER_JAEGER_PASSWORD`
When tracing is disabled, the impact on performance is negligible.
To see this in action:
1. Download latest Jaeger all-in-one from https://www.jaegertracing.io/download/
2. Run `jaeger-all-in-one` binary without any parameters.
3. Run `kopia --enable-jaeger-collector snapshot create ...`
4. Go to http://localhost:16686/search and search for traces
When enabled, metrics are pushed to the provided Prometheus Push
Gateway at the start and end of each command and periodically every
few seconds.
```
--metrics-push-addr=http://address:port
--metrics-push-interval=5s
--metrics-push-job=kopia
--metrics-push-grouping=a:b --metrics-push-grouping=c:d
--metrics-push-username=user
--metrics-push-password=pass
```
