fix(metrics): removed influx and added l2_state_size data

[antiyro]

Pull Request type

Please add the labels corresponding to the type of changes your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build-related changes
• Documentation content changes
• Testing
• Other (please describe):

What is the current behavior?

Resolves: #NA

What is the new behavior?

Does this introduce a breaking change?

Other information

[jbcaron]

The get_directory_size function looks efficient overall, but here are a few points to consider to ensure it doesn’t introduce unnecessary overhead:

• Error Handling: The function currently ignores errors when reading directory entries or fetching metadata.
• Concurrency: If the directory contains a large number of files or deeply nested structures, processing them sequentially could become a bottleneck. Consider using a concurrent approach to traverse the directory entries in parallel.
• Metrics Frequency Consideration: Since this function is used for metrics, consider how frequently these metrics need to be collected. If the function is called frequently, ensure that it does not introduce significant performance overhead.

[cchudant]

nit: its not really an endpoint

[antiyro]

sorry i forgot to change this

[cchudant]

I would prefer if we were using https://docs.rs/rocksdb/latest/rocksdb/struct.DBCommon.html#method.get_column_family_metadata_cf
which returns, for a given column, its size as

pub struct ColumnFamilyMetaData {
    // The size of this column family in bytes, which is equal to the sum of
    // the file size of its "levels".
    pub size: u64,
    // The name of the column family.
    pub name: String,
    // The number of files in this column family.
    pub file_count: usize,
}

Plus, we can do a sum gauge and a individual gauge for each column

[cchudant]

Perfect :)