# Background
Erigon currently uses a combination of Victoria Metrics and Prometheus
client for providing metrics.
We want to rationalize this and use only the Prometheus client library,
but we want to maintain the simplified Victoria Metrics methods for
constructing metrics.
This task is currently partly complete and needs to be finished to a
stage where we can remove the Victoria Metrics module from the Erigon
code base.
# Summary of changes
- Adds missing `NewCounter`, `NewSummary`, `NewHistogram`,
`GetOrCreateHistogram` functions to `erigon-lib/metrics` similar to the
interface VictoriaMetrics lib provides
- Minor tidy up for consistency inside `erigon-lib/metrics/set.go`
around return types (panic vs err consistency for funcs inside the
file), error messages, comments
- Replace all remaining usages of `github.com/VictoriaMetrics/metrics`
with `github.com/ledgerwatch/erigon-lib/metrics` - seamless (only import
changes) since interfaces match
This introduces _experimental_ RPC daemon run by embedded Silkworm
library. Same notes as in PR #8353 apply here plus the following ones:
- activated if `http` command-line option is enabled and `silkworm.path`
option is present, nothing more is required (i.e. currently, both block
execution and RPC daemon run by Silkworm when specifying
`silkworm.path`, just to keep things as simple as possible)
- only Execution API endpoints are implemented by Silkworm RPCDaemon,
whilst Engine API endpoints are still served by Erigon RPCDaemon
- some features are still missing, in particular:
- state change notification handling
- custom JSON RPC settings (i.e. Erigon RPC settings are not passed to
Silkworm yet)
This introduces _experimental_ block execution run by embedded Silkworm
API library:
- new command-line option `silkworm.path` to enable the feature by
specifying the path to the Silkworm library
- the Silkworm API shared library is dynamically loaded on-demand
- currently requires to build Silkworm library on the target machine
- available only on Linux at the moment: macOS has issue with [stack
size](https://github.com/golang/go/issues/28024) and Windows would
require [TDM-GCC-64](https://jmeubank.github.io/tdm-gcc/), both need
dedicated effort for an assessment
