remove materialized page cache

docs/pageserver-pagecache.md

@@ -5,4 +5,3 @@ TODO:
 - shared across tenants
 - store pages from layer files
 - store pages from "in-memory layer"
-- store materialized pages

docs/settings.md

@@ -134,7 +134,7 @@ depends on that, so if you change it, bad things will happen.
 
 #### page_cache_size
 
-Size of the page cache, to hold materialized page versions. Unit is
+Size of the page cache. Unit is
 number of 8 kB blocks. The default is 8192, which means 64 MB.
 
 #### max_file_descriptors

pageserver/src/metrics.rs

@@ -145,14 +145,6 @@ impl ReconstructTimeMetrics {
     }
 }
 
-pub(crate) static MATERIALIZED_PAGE_CACHE_HIT_DIRECT: Lazy<IntCounter> = Lazy::new(|| {
-    register_int_counter!(
-        "pageserver_materialized_cache_hits_direct_total",
-        "Number of cache hits from materialized page cache without redo",
-    )
-    .expect("failed to define a metric")
-});
-
 pub(crate) struct ReconstructDataTimeMetrics {
     singular: Histogram,
     vectored: Histogram,
@@ -182,14 +174,6 @@ pub(crate) static GET_RECONSTRUCT_DATA_TIME: Lazy<ReconstructDataTimeMetrics> =
     }
 });
 
-pub(crate) static MATERIALIZED_PAGE_CACHE_HIT: Lazy<IntCounter> = Lazy::new(|| {
-    register_int_counter!(
-        "pageserver_materialized_cache_hits_total",
-        "Number of cache hits from materialized page cache",
-    )
-    .expect("failed to define a metric")
-});
-
 pub(crate) struct GetVectoredLatency {
     map: EnumMap<TaskKind, Option<Histogram>>,
 }
@@ -298,12 +282,8 @@ pub(crate) static SCAN_LATENCY: Lazy<ScanLatency> = Lazy::new(|| {
 });
 
 pub(crate) struct PageCacheMetricsForTaskKind {
-    pub read_accesses_materialized_page: IntCounter,
     pub read_accesses_immutable: IntCounter,
-
     pub read_hits_immutable: IntCounter,
-    pub read_hits_materialized_page_exact: IntCounter,
-    pub read_hits_materialized_page_older_lsn: IntCounter,
 }
 
 pub(crate) struct PageCacheMetrics {
@@ -336,16 +316,6 @@ pub(crate) static PAGE_CACHE: Lazy<PageCacheMetrics> = Lazy::new(|| PageCacheMet
             let content_kind = <PageContentKind as enum_map::Enum>::from_usize(content_kind);
             let content_kind: &'static str = content_kind.into();
             PageCacheMetricsForTaskKind {
-                read_accesses_materialized_page: {
-                    PAGE_CACHE_READ_ACCESSES
-                        .get_metric_with_label_values(&[
-                            task_kind,
-                            "materialized_page",
-                            content_kind,
-                        ])
-                        .unwrap()
-                },
-
                 read_accesses_immutable: {
                     PAGE_CACHE_READ_ACCESSES
                         .get_metric_with_label_values(&[task_kind, "immutable", content_kind])
@@ -357,28 +327,6 @@ pub(crate) static PAGE_CACHE: Lazy<PageCacheMetrics> = Lazy::new(|| PageCacheMet
                         .get_metric_with_label_values(&[task_kind, "immutable", content_kind, "-"])
                         .unwrap()
                 },
-
-                read_hits_materialized_page_exact: {
-                    PAGE_CACHE_READ_HITS
-                        .get_metric_with_label_values(&[
-                            task_kind,
-                            "materialized_page",
-                            content_kind,
-                            "exact",
-                        ])
-                        .unwrap()
-                },
-
-                read_hits_materialized_page_older_lsn: {
-                    PAGE_CACHE_READ_HITS
-                        .get_metric_with_label_values(&[
-                            task_kind,
-                            "materialized_page",
-                            content_kind,
-                            "older_lsn",
-                        ])
-                        .unwrap()
-                },
             }
         }))
     })),
@@ -394,7 +342,6 @@ pub(crate) struct PageCacheSizeMetrics {
     pub max_bytes: UIntGauge,
 
     pub current_bytes_immutable: UIntGauge,
-    pub current_bytes_materialized_page: UIntGauge,
 }
 
 static PAGE_CACHE_SIZE_CURRENT_BYTES: Lazy<UIntGaugeVec> = Lazy::new(|| {
@@ -420,11 +367,6 @@ pub(crate) static PAGE_CACHE_SIZE: Lazy<PageCacheSizeMetrics> =
                 .get_metric_with_label_values(&["immutable"])
                 .unwrap()
         },
-        current_bytes_materialized_page: {
-            PAGE_CACHE_SIZE_CURRENT_BYTES
-                .get_metric_with_label_values(&["materialized_page"])
-                .unwrap()
-        },
     });
 
 pub(crate) mod page_cache_eviction_metrics {
@@ -2918,13 +2860,11 @@ pub fn preinitialize_metrics() {
     // FIXME(4813): make it so that we have no top level metrics as this fn will easily fall out of
     // order:
     // - global metrics reside in a Lazy<PageserverMetrics>
-    //   - access via crate::metrics::PS_METRICS.materialized_page_cache_hit.inc()
+    //   - access via crate::metrics::PS_METRICS.some_metric.inc()
     // - could move the statics into TimelineMetrics::new()?
 
     // counters
     [
-        &MATERIALIZED_PAGE_CACHE_HIT,
-        &MATERIALIZED_PAGE_CACHE_HIT_DIRECT,
         &UNEXPECTED_ONDEMAND_DOWNLOADS,
         &WALRECEIVER_STARTED_CONNECTIONS,
         &WALRECEIVER_BROKER_UPDATES,