chore: update metriken library (#100)

Updates the metriken metrics library to version 0.2.1 and converts
all metrics declarations to using the attribute macro. This will
allow us to easily add additional metric metadata later.

Cargo.toml

@@ -55,7 +55,7 @@ httparse = "1.8.0"
 libc = "0.2.139"
 log = "0.4.17"
 memmap2 = "0.5.8"
-metriken = "0.1.1"
+metriken = "0.2.3"
 metrohash = "1.0.6"
 mio = "0.8.5"
 nom = "7.1.3"
@@ -65,7 +65,7 @@ quote = "1.0.23"
 rand = "0.8.5"
 rand_chacha = "0.3.1"
 rand_xoshiro = "0.6.0"
-ringlog = "0.1.0"
+ringlog = "0.2.0"
 serde = "1.0.152"
 serde_json = "1.0.91"
 signal-hook = "0.3.15"

src/common/src/metrics.rs

@@ -27,7 +27,8 @@ macro_rules! test_no_duplicates {
 
 pub use test_no_duplicates;
 
-gauge!(PID, "the process id");
+#[metric(name = "pid", description = "the process id")]
+pub static PID: Gauge = Gauge::new();
 
 pub fn init() {
     PID.set(std::process::id().into());