chore: add dynamic cache size adjustment for InvertedIndexConfig (#4433)

* Add dynamic cache size adjustment for InvertedIndexConfig

* Increase cache sizes in integration tests for HTTP

 - Updated `metadata_cache_size` from 32MiB to 64MiB

* Remove cache size settings from config and update drop_lines_with_inconsistent_results function to handle them

* Add cache size configurations for inverted index metadata and content

 - Introduced `metadata_cache_size` with a default of 64MiB.
 - Introduced `content_cache_size` with a default of 128MiB.

* chore/index-content-cache-default-size: Add cache size configuration options for Mito engine's inverted index

config/config.md

@@ -129,6 +129,8 @@
 | `region_engine.mito.inverted_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
 | `region_engine.mito.inverted_index.mem_threshold_on_create` | String | `auto` | Memory threshold for performing an external sort during index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
 | `region_engine.mito.inverted_index.intermediate_path` | String | `""` | Deprecated, use `region_engine.mito.index.aux_path` instead. |
+| `region_engine.mito.inverted_index.metadata_cache_size` | String | `64MiB` | Cache size for inverted index metadata. |
+| `region_engine.mito.inverted_index.content_cache_size` | String | `128MiB` | Cache size for inverted index content. |
 | `region_engine.mito.fulltext_index` | -- | -- | The options for full-text index in Mito engine. |
 | `region_engine.mito.fulltext_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
 | `region_engine.mito.fulltext_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |

config/standalone.example.toml

@@ -459,6 +459,12 @@ mem_threshold_on_create = "auto"
 ## Deprecated, use `region_engine.mito.index.aux_path` instead.
 intermediate_path = ""
 
+## Cache size for inverted index metadata.
+metadata_cache_size = "64MiB"
+
+## Cache size for inverted index content.
+content_cache_size = "128MiB"
+
 ## The options for full-text index in Mito engine.
 [region_engine.mito.fulltext_index]
 

src/mito2/src/config.rs

@@ -39,6 +39,8 @@ const DEFAULT_SCAN_CHANNEL_SIZE: usize = 32;
 const GLOBAL_WRITE_BUFFER_SIZE_FACTOR: u64 = 8;
 /// Use `1/SST_META_CACHE_SIZE_FACTOR` of OS memory size as SST meta cache size in default mode
 const SST_META_CACHE_SIZE_FACTOR: u64 = 32;
+/// Use `1/INDEX_CONTENT_CACHE_SIZE_FACTOR` of OS memory size for inverted index file content cache by default.
+const INDEX_CONTENT_CACHE_SIZE_FACTOR: u64 = 32;
 /// Use `1/MEM_CACHE_SIZE_FACTOR` of OS memory size as mem cache size in default mode
 const MEM_CACHE_SIZE_FACTOR: u64 = 16;
 /// Use `1/INDEX_CREATE_MEM_THRESHOLD_FACTOR` of OS memory size as mem threshold for creating index
@@ -389,19 +391,35 @@ pub struct InvertedIndexConfig {
     pub content_cache_size: ReadableSize,
 }
 
+impl InvertedIndexConfig {
+    /// Adjusts the cache size of [InvertedIndexConfig] according to system memory size.
+    fn adjust_cache_size(&mut self, sys_memory: ReadableSize) {
+        let content_cache_size = cmp::min(
+            sys_memory / INDEX_CONTENT_CACHE_SIZE_FACTOR,
+            ReadableSize::mb(128),
+        );
+        self.content_cache_size = content_cache_size;
+    }
+}
+
 impl Default for InvertedIndexConfig {
     #[allow(deprecated)]
     fn default() -> Self {
-        Self {
+        let mut index_config = Self {
             create_on_flush: Mode::Auto,
             create_on_compaction: Mode::Auto,
             apply_on_query: Mode::Auto,
             mem_threshold_on_create: MemoryThreshold::Auto,
             write_buffer_size: ReadableSize::mb(8),
             intermediate_path: String::new(),
-            metadata_cache_size: ReadableSize::mb(32),
-            content_cache_size: ReadableSize::mb(32),
+            metadata_cache_size: ReadableSize::mb(64),
+            content_cache_size: ReadableSize::mb(128),
+        };
+
+        if let Some(sys_memory) = common_config::utils::get_sys_total_memory() {
+            index_config.adjust_cache_size(sys_memory);
         }
+        index_config
     }
 }
 

tests-integration/tests/http.rs

@@ -839,8 +839,6 @@ create_on_flush = "auto"
 create_on_compaction = "auto"
 apply_on_query = "auto"
 mem_threshold_on_create = "auto"
-metadata_cache_size = "32MiB"
-content_cache_size = "32MiB"
 
 [region_engine.mito.fulltext_index]
 create_on_flush = "auto"
@@ -889,6 +887,8 @@ fn drop_lines_with_inconsistent_results(input: String) -> String {
         "vector_cache_size =",
         "page_cache_size =",
         "selector_result_cache_size =",
+        "metadata_cache_size =",
+        "content_cache_size =",
     ];
 
     input