Adjust nofiles within Blocktree::open() for all ledger/ users (#6737)

automerge

ledger/Cargo.toml

@@ -19,6 +19,7 @@ dlopen_derive = "0.1.4"
 fs_extra = "1.1.0"
 itertools = "0.8.1"
 lazy_static = "1.4.0"
+libc = "0.2.65"
 log = { version = "0.4.8" }
 rand = "0.6.5"
 rand_chacha = "0.1.1"

ledger/src/blocktree.rs

@@ -135,6 +135,8 @@ impl Blocktree {
         fs::create_dir_all(&ledger_path)?;
         let blocktree_path = ledger_path.join(BLOCKTREE_DIRECTORY);
 
+        adjust_ulimit_nofile();
+
         // Open the database
         let db = Database::open(&blocktree_path)?;
 
@@ -1834,6 +1836,45 @@ pub fn make_chaining_slot_entries(
     slots_shreds_and_entries
 }
 
+#[cfg(not(unix))]
+fn adjust_ulimit_nofile() {}
+
+#[cfg(unix)]
+fn adjust_ulimit_nofile() {
+    // Rocks DB likes to have many open files.  The default open file descriptor limit is
+    // usually not enough
+    let desired_nofile = 65000;
+
+    fn get_nofile() -> libc::rlimit {
+        let mut nofile = libc::rlimit {
+            rlim_cur: 0,
+            rlim_max: 0,
+        };
+        if unsafe { libc::getrlimit(libc::RLIMIT_NOFILE, &mut nofile) } != 0 {
+            warn!("getrlimit(RLIMIT_NOFILE) failed");
+        }
+        nofile
+    }
+
+    let mut nofile = get_nofile();
+    if nofile.rlim_cur < desired_nofile {
+        nofile.rlim_cur = desired_nofile;
+        if unsafe { libc::setrlimit(libc::RLIMIT_NOFILE, &nofile) } != 0 {
+            error!(
+                "Unable to increase the maximum open file descriptor limit to {}",
+                desired_nofile
+            );
+
+            if cfg!(target_os = "macos") {
+                error!("On mac OS you may need to run |sudo launchctl limit maxfiles 65536 200000| first");
+            }
+        }
+
+        nofile = get_nofile();
+    }
+    info!("Maximum open file descriptors: {}", nofile.rlim_cur);
+}
+
 #[cfg(test)]
 pub mod tests {
     use super::*;