[archivist] Fix memory usage issue.
This CL fixes high memory usage in Archivist:
- Switch to correct constant for in-memory buffering.
- Switch to buffer_unordered to support out of order execution of
inspect snapshots.
- Increase snapshot limit from 2 to 4, to provide for better backfilling
and throughput.
Still need to limit overall work between archive accessors.
Bug: 62685
Change-Id: I616028314663d6d062cff86eec25ab4f3427a068
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/443634
Reviewed-by: Adam Perry <adamperry@google.com>
Testability-Review: Adam Perry <adamperry@google.com>
Commit-Queue: Adam Perry <adamperry@google.com>
Commit-Queue: Christopher Johnson <crjohns@google.com>
diff --git a/src/diagnostics/archivist/src/constants.rs b/src/diagnostics/archivist/src/constants.rs
index 4ad1c59..4274d52 100644
--- a/src/diagnostics/archivist/src/constants.rs
+++ b/src/diagnostics/archivist/src/constants.rs
@@ -26,7 +26,7 @@
/// The maximum number of Inspect files that can be simultaneously snapshotted and formatted per
/// reader.
-pub const MAXIMUM_SIMULTANEOUS_SNAPSHOTS_PER_READER: usize = 2;
+pub const MAXIMUM_SIMULTANEOUS_SNAPSHOTS_PER_READER: usize = 4;
/// The maximum number of bytes in a formatted content VMO.
pub const FORMATTED_CONTENT_CHUNK_SIZE_TARGET: usize = 1 << 20; // 1 MiB
diff --git a/src/diagnostics/archivist/src/inspect/mod.rs b/src/diagnostics/archivist/src/inspect/mod.rs
index 5a2008a..8975a2c 100644
--- a/src/diagnostics/archivist/src/inspect/mod.rs
+++ b/src/diagnostics/archivist/src/inspect/mod.rs
@@ -132,7 +132,7 @@
}
})
// buffer a small number in memory in case later components time out
- .buffered(constants::IN_MEMORY_SNAPSHOT_LIMIT)
+ .buffer_unordered(constants::MAXIMUM_SIMULTANEOUS_SNAPSHOTS_PER_READER)
// filter each component's inspect
.map(move |populated| server.filter_snapshot(populated))
// turn each of the vecs of filtered snapshots into their own streams
