validator cli: Clarifies snapshot intervals (#2128)

validator/src/cli.rs

@@ -499,20 +499,21 @@ pub fn app<'a>(version: &'a str, default_args: &'a DefaultArgs) -> App<'a, 'a> {
                 .long("no-incremental-snapshots")
                 .takes_value(false)
                 .help("Disable incremental snapshots")
-                .long_help(
-                    "Disable incremental snapshots by setting this flag. When enabled, \
-                     --snapshot-interval-slots will set the incremental snapshot interval. To set \
-                     the full snapshot interval, use --full-snapshot-interval-slots.",
-                ),
         )
         .arg(
-            Arg::with_name("incremental_snapshot_interval_slots")
-                .long("incremental-snapshot-interval-slots")
-                .alias("snapshot-interval-slots")
+            Arg::with_name("snapshot_interval_slots")
+                .long("snapshot-interval-slots")
+                .alias("incremental-snapshot-interval-slots")
                 .value_name("NUMBER")
                 .takes_value(true)
                 .default_value(&default_args.incremental_snapshot_archive_interval_slots)
-                .help("Number of slots between generating snapshots, 0 to disable snapshots"),
+                .help("Number of slots between generating snapshots")
+                .long_help(
+                    "Number of slots between generating snapshots. \
+                     If incremental snapshots are enabled, this sets the incremental snapshot interval. \
+                     If incremental snapshots are disabled, this sets the full snapshot interval. \
+                     Setting this to 0 disables all snapshots.",
+                ),
         )
         .arg(
             Arg::with_name("full_snapshot_interval_slots")
@@ -520,9 +521,10 @@ pub fn app<'a>(version: &'a str, default_args: &'a DefaultArgs) -> App<'a, 'a> {
                 .value_name("NUMBER")
                 .takes_value(true)
                 .default_value(&default_args.full_snapshot_archive_interval_slots)
-                .help(
+                .help("Number of slots between generating full snapshots")
+                .long_help(
                     "Number of slots between generating full snapshots. Must be a multiple of the \
-                     incremental snapshot interval.",
+                     incremental snapshot interval. Only used when incremental snapshots are enabled.",
                 ),
         )
         .arg(

validator/src/main.rs

@@ -1665,27 +1665,42 @@ pub fn main() {
                 })
             });
 
-    let incremental_snapshot_interval_slots =
-        value_t_or_exit!(matches, "incremental_snapshot_interval_slots", u64);
-    let (full_snapshot_archive_interval_slots, incremental_snapshot_archive_interval_slots) =
-        if incremental_snapshot_interval_slots > 0 {
-            if !matches.is_present("no_incremental_snapshots") {
-                (
-                    value_t_or_exit!(matches, "full_snapshot_interval_slots", u64),
-                    incremental_snapshot_interval_slots,
-                )
-            } else {
-                (
-                    incremental_snapshot_interval_slots,
-                    DISABLED_SNAPSHOT_ARCHIVE_INTERVAL,
-                )
-            }
-        } else {
+    let (full_snapshot_archive_interval_slots, incremental_snapshot_archive_interval_slots) = match (
+        !matches.is_present("no_incremental_snapshots"),
+        value_t_or_exit!(matches, "snapshot_interval_slots", u64),
+    ) {
+        (_, 0) => {
+            // snapshots are disabled
             (
                 DISABLED_SNAPSHOT_ARCHIVE_INTERVAL,
                 DISABLED_SNAPSHOT_ARCHIVE_INTERVAL,
             )
-        };
+        }
+        (true, incremental_snapshot_interval_slots) => {
+            // incremental snapshots are enabled
+            // use --snapshot-interval-slots for the incremental snapshot interval
+            (
+                value_t_or_exit!(matches, "full_snapshot_interval_slots", u64),
+                incremental_snapshot_interval_slots,
+            )
+        }
+        (false, full_snapshot_interval_slots) => {
+            // incremental snapshots are *disabled*
+            // use --snapshot-interval-slots for the *full* snapshot interval
+            // also warn if --full-snapshot-interval-slots was specified
+            if matches.occurrences_of("full_snapshot_interval_slots") > 0 {
+                warn!(
+                    "Incremental snapshots are disabled, yet --full-snapshot-interval-slots was specified! \
+                     Note that --full-snapshot-interval-slots is *ignored* when incremental snapshots are disabled. \
+                     Use --snapshot-interval-slots instead.",
+                );
+            }
+            (
+                full_snapshot_interval_slots,
+                DISABLED_SNAPSHOT_ARCHIVE_INTERVAL,
+            )
+        }
+    };
 
     validator_config.snapshot_config = SnapshotConfig {
         usage: if full_snapshot_archive_interval_slots == DISABLED_SNAPSHOT_ARCHIVE_INTERVAL {
@@ -1712,29 +1727,30 @@ pub fn main() {
         incremental_snapshot_archive_interval_slots,
     );
 
+    info!(
+        "Snapshot configuration: full snapshot interval: {} slots, incremental snapshot interval: {} slots",
+        if full_snapshot_archive_interval_slots == DISABLED_SNAPSHOT_ARCHIVE_INTERVAL {
+            "disabled".to_string()
+        } else {
+            full_snapshot_archive_interval_slots.to_string()
+        },
+        if incremental_snapshot_archive_interval_slots == DISABLED_SNAPSHOT_ARCHIVE_INTERVAL {
+            "disabled".to_string()
+        } else {
+            incremental_snapshot_archive_interval_slots.to_string()
+        },
+    );
+
     if !is_snapshot_config_valid(
         &validator_config.snapshot_config,
         validator_config.accounts_hash_interval_slots,
     ) {
         eprintln!(
             "Invalid snapshot configuration provided: snapshot intervals are incompatible. \
-             \n\t- full snapshot interval MUST be a multiple of incremental snapshot interval (if \
-             enabled)\
-             \n\t- full snapshot interval MUST be larger than incremental snapshot \
-             interval (if enabled)\
-             \nSnapshot configuration values:\
-             \n\tfull snapshot interval: {}\
-             \n\tincremental snapshot interval: {}",
-            if full_snapshot_archive_interval_slots == DISABLED_SNAPSHOT_ARCHIVE_INTERVAL {
-                "disabled".to_string()
-            } else {
-                full_snapshot_archive_interval_slots.to_string()
-            },
-            if incremental_snapshot_archive_interval_slots == DISABLED_SNAPSHOT_ARCHIVE_INTERVAL {
-                "disabled".to_string()
-            } else {
-                incremental_snapshot_archive_interval_slots.to_string()
-            },
+             \n\t- full snapshot interval MUST be a multiple of incremental snapshot interval \
+             (if enabled) \
+             \n\t- full snapshot interval MUST be larger than incremental snapshot interval \
+             (if enabled)",
         );
         exit(1);
     }