scmstore: add counter for indexedlog rotations

Summary: Expose a counter for number of indexedlog rotations. We don't want the hgcache logs to rotate too frequently (because that drops all the data in the final log), and this will help us see how often they rotate.

Reviewed By: sggutier

Differential Revision: D66903539

fbshipit-source-id: 1526594e454944b376b943ae84547dcff2aab5de

eden/scm/lib/indexedlog/src/rotate.rs

@@ -12,7 +12,9 @@ use std::fs;
 use std::io;
 use std::path::Path;
 use std::path::PathBuf;
+use std::sync::atomic::AtomicU64;
 use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 use std::sync::atomic::Ordering::SeqCst;
 
 use minibytes::Bytes;
@@ -37,6 +39,8 @@ use crate::repair::OpenOptionsRepair;
 use crate::repair::RepairMessage;
 use crate::utils;
 
+pub static ROTATE_COUNT: AtomicU64 = AtomicU64::new(0);
+
 /// A collection of [`Log`]s that get rotated or deleted automatically when they
 /// exceed size or count limits.
 ///
@@ -586,6 +590,8 @@ impl RotateLog {
     /// callsite makes sure that [`Log`]s are consistent (ex. up-to-date,
     /// and do not have dirty entries in non-writable logs).
     fn rotate_internal(&mut self, lock: &ScopedDirLock) -> crate::Result<()> {
+        ROTATE_COUNT.fetch_add(1, Ordering::Relaxed);
+
         let span = debug_span!("RotateLog::rotate", latest = self.latest as u32);
         if let Some(dir) = &self.dir {
             span.record("dir", dir.to_string_lossy().as_ref());

eden/scm/lib/revisionstore/src/scmstore/file.rs

@@ -28,6 +28,7 @@ use clientinfo::set_client_request_info_thread_local;
 use crossbeam::channel::unbounded;
 use indexedlog::log::AUTO_SYNC_COUNT;
 use indexedlog::log::SYNC_COUNT;
+use indexedlog::rotate::ROTATE_COUNT;
 use itertools::Itertools;
 use minibytes::Bytes;
 use parking_lot::Mutex;
@@ -140,6 +141,7 @@ macro_rules! try_local_content {
 static FILESTORE_FLUSH_COUNT: Counter = Counter::new_counter("scmstore.file.flush");
 static INDEXEDLOG_SYNC_COUNT: Counter = Counter::new_counter("scmstore.indexedlog.sync");
 static INDEXEDLOG_AUTO_SYNC_COUNT: Counter = Counter::new_counter("scmstore.indexedlog.auto_sync");
+static INDEXEDLOG_ROTATE_COUNT: Counter = Counter::new_counter("scmstore.indexedlog.rotate");
 
 impl FileStore {
     /// Get the "local content" without going through the heavyweight "fetch" API.
@@ -329,6 +331,7 @@ impl FileStore {
             // These aren't technically filestore specific, but this will keep them updated.
             INDEXEDLOG_SYNC_COUNT.add(SYNC_COUNT.swap(0, Ordering::Relaxed) as usize);
             INDEXEDLOG_AUTO_SYNC_COUNT.add(AUTO_SYNC_COUNT.swap(0, Ordering::Relaxed) as usize);
+            INDEXEDLOG_ROTATE_COUNT.add(ROTATE_COUNT.swap(0, Ordering::Relaxed) as usize);
 
             if let Some(activity_logger) = activity_logger {
                 if let Err(err) = activity_logger.lock().log_file_fetch(

eden/scm/tests/test-remotefilelog-prefetch.t

@@ -43,7 +43,8 @@ Prefetch (and also check we get counters):
   scmstore.file.fetch.indexedlog.local.singles: 1
   scmstore.file.fetch.indexedlog.local.time: * (glob) (?)
   scmstore.file.flush: * (glob)
-  scmstore.indexedlog.sync: * (glob)
+  scmstore.indexedlog.rotate: * (glob) (?)
+  scmstore.indexedlog.sync: * (glob) (?)
   scmstore.tree.fetch.edenapi.keys: 1
   scmstore.tree.fetch.edenapi.requests: 1
   scmstore.tree.fetch.edenapi.singles: 1