diff --git a/pageserver/src/metrics.rs b/pageserver/src/metrics.rs index 9aff5220f59e..ede6b41a7509 100644 --- a/pageserver/src/metrics.rs +++ b/pageserver/src/metrics.rs @@ -613,7 +613,23 @@ pub(crate) static CIRCUIT_BREAKERS_UNBROKEN: Lazy = Lazy::new(|| { pub(crate) static COMPRESSION_IMAGE_INPUT_BYTES: Lazy = Lazy::new(|| { register_int_counter!( "pageserver_compression_image_in_bytes_total", - "Size of uncompressed data written into image layers" + "Size of data written into image layers before compression" + ) + .expect("failed to define a metric") +}); + +pub(crate) static COMPRESSION_IMAGE_INPUT_BYTES_CONSIDERED: Lazy = Lazy::new(|| { + register_int_counter!( + "pageserver_compression_image_in_bytes_considered", + "Size of potentially compressible data written into image layers before compression" + ) + .expect("failed to define a metric") +}); + +pub(crate) static COMPRESSION_IMAGE_INPUT_BYTES_CHOSEN: Lazy = Lazy::new(|| { + register_int_counter!( + "pageserver_compression_image_in_bytes_chosen", + "Size of data whose compressed form was written into image layers" ) .expect("failed to define a metric") }); diff --git a/pageserver/src/tenant/blob_io.rs b/pageserver/src/tenant/blob_io.rs index 791eefebe989..8e9d349ca88c 100644 --- a/pageserver/src/tenant/blob_io.rs +++ b/pageserver/src/tenant/blob_io.rs @@ -28,6 +28,12 @@ use crate::virtual_file::VirtualFile; use std::cmp::min; use std::io::{Error, ErrorKind}; +#[derive(Copy, Clone, Debug)] +pub struct CompressionInfo { + pub written_compressed: bool, + pub compressed_size: Option, +} + impl<'a> BlockCursor<'a> { /// Read a blob into a new buffer. pub async fn read_blob( @@ -273,8 +279,10 @@ impl BlobWriter { srcbuf: B, ctx: &RequestContext, ) -> (B::Buf, Result) { - self.write_blob_maybe_compressed(srcbuf, ctx, ImageCompressionAlgorithm::Disabled) - .await + let (buf, res) = self + .write_blob_maybe_compressed(srcbuf, ctx, ImageCompressionAlgorithm::Disabled) + .await; + (buf, res.map(|(off, _compression_info)| off)) } /// Write a blob of data. Returns the offset that it was written to, @@ -284,8 +292,12 @@ impl BlobWriter { srcbuf: B, ctx: &RequestContext, algorithm: ImageCompressionAlgorithm, - ) -> (B::Buf, Result) { + ) -> (B::Buf, Result<(u64, CompressionInfo), Error>) { let offset = self.offset; + let mut compression_info = CompressionInfo { + written_compressed: false, + compressed_size: None, + }; let len = srcbuf.bytes_init(); @@ -328,7 +340,9 @@ impl BlobWriter { encoder.write_all(&slice[..]).await.unwrap(); encoder.shutdown().await.unwrap(); let compressed = encoder.into_inner(); + compression_info.compressed_size = Some(compressed.len()); if compressed.len() < len { + compression_info.written_compressed = true; let compressed_len = compressed.len(); compressed_buf = Some(compressed); (BYTE_ZSTD, compressed_len, slice.into_inner()) @@ -359,7 +373,7 @@ impl BlobWriter { } else { self.write_all(srcbuf, ctx).await }; - (srcbuf, res.map(|_| offset)) + (srcbuf, res.map(|_| (offset, compression_info))) } } @@ -416,12 +430,14 @@ pub(crate) mod tests { let mut wtr = BlobWriter::::new(file, 0); for blob in blobs.iter() { let (_, res) = if compression { - wtr.write_blob_maybe_compressed( - blob.clone(), - ctx, - ImageCompressionAlgorithm::Zstd { level: Some(1) }, - ) - .await + let res = wtr + .write_blob_maybe_compressed( + blob.clone(), + ctx, + ImageCompressionAlgorithm::Zstd { level: Some(1) }, + ) + .await; + (res.0, res.1.map(|(off, _)| off)) } else { wtr.write_blob(blob.clone(), ctx).await }; diff --git a/pageserver/src/tenant/storage_layer/delta_layer.rs b/pageserver/src/tenant/storage_layer/delta_layer.rs index 229d1e36082b..f9becf53ff02 100644 --- a/pageserver/src/tenant/storage_layer/delta_layer.rs +++ b/pageserver/src/tenant/storage_layer/delta_layer.rs @@ -467,7 +467,7 @@ impl DeltaLayerWriterInner { .write_blob_maybe_compressed(val, ctx, compression) .await; let off = match res { - Ok(off) => off, + Ok((off, _)) => off, Err(e) => return (val, Err(anyhow::anyhow!(e))), }; diff --git a/pageserver/src/tenant/storage_layer/image_layer.rs b/pageserver/src/tenant/storage_layer/image_layer.rs index 44ba68549059..08db27514a21 100644 --- a/pageserver/src/tenant/storage_layer/image_layer.rs +++ b/pageserver/src/tenant/storage_layer/image_layer.rs @@ -734,6 +734,14 @@ struct ImageLayerWriterInner { // Total uncompressed bytes passed into put_image uncompressed_bytes: u64, + // Like `uncompressed_bytes`, + // but only of images we might consider for compression + uncompressed_bytes_eligible: u64, + + // Like `uncompressed_bytes`, but only of images + // where we have chosen their compressed form + uncompressed_bytes_chosen: u64, + blob_writer: BlobWriter, tree: DiskBtreeBuilder, } @@ -790,6 +798,8 @@ impl ImageLayerWriterInner { tree: tree_builder, blob_writer, uncompressed_bytes: 0, + uncompressed_bytes_eligible: 0, + uncompressed_bytes_chosen: 0, }; Ok(writer) @@ -808,13 +818,22 @@ impl ImageLayerWriterInner { ) -> anyhow::Result<()> { ensure!(self.key_range.contains(&key)); let compression = self.conf.image_compression; - self.uncompressed_bytes += img.len() as u64; + let uncompressed_len = img.len() as u64; + self.uncompressed_bytes += uncompressed_len; let (_img, res) = self .blob_writer .write_blob_maybe_compressed(img, ctx, compression) .await; // TODO: re-use the buffer for `img` further upstack - let off = res?; + let (off, compression_info) = res?; + if compression_info.compressed_size.is_some() { + // The image has been considered for compression at least + self.uncompressed_bytes_eligible += uncompressed_len; + } + if compression_info.written_compressed { + // The image has been compressed + self.uncompressed_bytes_chosen += uncompressed_len; + } let mut keybuf: [u8; KEY_SIZE] = [0u8; KEY_SIZE]; key.write_to_byte_slice(&mut keybuf); @@ -837,6 +856,9 @@ impl ImageLayerWriterInner { // Calculate compression ratio let compressed_size = self.blob_writer.size() - PAGE_SZ as u64; // Subtract PAGE_SZ for header crate::metrics::COMPRESSION_IMAGE_INPUT_BYTES.inc_by(self.uncompressed_bytes); + crate::metrics::COMPRESSION_IMAGE_INPUT_BYTES_CONSIDERED + .inc_by(self.uncompressed_bytes_eligible); + crate::metrics::COMPRESSION_IMAGE_INPUT_BYTES_CHOSEN.inc_by(self.uncompressed_bytes_chosen); crate::metrics::COMPRESSION_IMAGE_OUTPUT_BYTES.inc_by(compressed_size); let mut file = self.blob_writer.into_inner();