feat: ensure reserved memory for computing tasks on compute node star…

…ting (risingwavelabs#7670)

The total memory of a CN consists of:

1. computing memory (both stream & batch)
2. storage memory (block cache, meta cache, etc.)
3. memory for system usage

That is to say, we have **_CN total memory_ = _computing memory_ + _storage memory_ + _system memory_**, and both _CN total memory_ and _storage memory_ are configured by the user currently. This PR is to ensure that _computing memory_ and  _system memory_ are correctly reserved,, i.e. **_computing memory_ + _system memory_ = _CN total memory_ - _storage memory_ > a given amount of memory**. We set this "given amount of memory" as 1G for now (512M for computing and 512M for system). The check is performed on CN starting.

Approved-By: fuyufjh
Approved-By: hzxa21

risedev.yml

@@ -672,7 +672,7 @@ template:
     # Whether to enable in-memory pure KV state backend
     enable-in-memory-kv-state-backend: false
 
-    # Total available memory to LRU Manager in bytes
+    # Total available memory for the compute node in bytes
     total-memory-bytes: 8589934592
 
     # Parallelism of tasks per compute node

src/common/src/config.rs

@@ -276,7 +276,7 @@ pub struct StorageConfig {
     /// Maximum shared buffer size, writes attempting to exceed the capacity will stall until there
     /// is enough space.
     #[serde(default = "default::storage::shared_buffer_capacity_mb")]
-    pub shared_buffer_capacity_mb: u32,
+    pub shared_buffer_capacity_mb: usize,
 
     /// State store url.
     #[serde(default = "default::storage::state_store")]
@@ -348,6 +348,32 @@ impl Default for StorageConfig {
     }
 }
 
+impl StorageConfig {
+    /// Checks whether an embedded compactor starts with a compute node.
+    #[inline(always)]
+    pub fn embedded_compactor_enabled(&self) -> bool {
+        // We treat `hummock+memory-shared` as a shared storage, so we won't start the compactor
+        // along with the compute node.
+        self.state_store == "hummock+memory"
+            || self.state_store.starts_with("hummock+disk")
+            || self.disable_remote_compactor
+    }
+
+    /// The maximal memory that storage components may use based on the configurations. Note that
+    /// this is the total storage memory for one compute node instead of the whole cluster.
+    pub fn total_storage_memory_limit_mb(&self) -> usize {
+        let total_memory = self.block_cache_capacity_mb
+            + self.meta_cache_capacity_mb
+            + self.shared_buffer_capacity_mb
+            + self.file_cache.total_buffer_capacity_mb;
+        if self.embedded_compactor_enabled() {
+            total_memory + self.compactor_memory_limit_mb
+        } else {
+            total_memory
+        }
+    }
+}
+
 /// The subsection `[storage.file_cache]` in `risingwave.toml`.
 ///
 /// It's put at [`StorageConfig::file_cache`].
@@ -533,7 +559,7 @@ mod default {
             4
         }
 
-        pub fn shared_buffer_capacity_mb() -> u32 {
+        pub fn shared_buffer_capacity_mb() -> usize {
             1024
         }
 

src/compute/Cargo.toml

@@ -33,6 +33,7 @@ num-traits = "0.2"
 parking_lot = "0.12"
 paste = "1"
 pprof = { version = "0.11", features = ["flamegraph"] }
+pretty-bytes = "0.2.2"
 prometheus = { version = "0.13" }
 prost = "0.11"
 risingwave_batch = { path = "../batch" }

src/compute/src/lib.rs

@@ -75,7 +75,7 @@ pub struct ComputeNodeOpts {
     #[clap(long, env = "RW_CONFIG_PATH", default_value = "")]
     pub config_path: String,
 
-    /// Total available memory in bytes, used by LRU Manager
+    /// Total available memory for the compute node in bytes. Used by both computing and storage.
     #[clap(long, env = "RW_TOTAL_MEMORY_BYTES", default_value_t = default_total_memory_bytes())]
     pub total_memory_bytes: usize,
 

src/compute/src/memory_management/memory_manager.rs

@@ -21,6 +21,12 @@ use risingwave_common::util::epoch::Epoch;
 use risingwave_stream::executor::monitor::StreamingMetrics;
 use risingwave_stream::task::LocalStreamManager;
 
+/// The minimal memory requirement of computing tasks in megabytes.
+pub const MIN_COMPUTE_MEMORY_MB: usize = 512;
+/// The memory reserved for system usage (stack and code segment of processes, allocation overhead,
+/// network buffer, etc.) in megabytes.
+pub const SYSTEM_RESERVED_MEMORY_MB: usize = 512;
+
 /// When `enable_managed_cache` is set, compute node will launch a [`GlobalMemoryManager`] to limit
 /// the memory usage.
 #[cfg_attr(not(target_os = "linux"), expect(dead_code))]

src/compute/src/server.rs

@@ -17,11 +17,13 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use async_stack_trace::StackTraceManager;
+use pretty_bytes::converter::convert;
 use risingwave_batch::executor::BatchTaskMetrics;
 use risingwave_batch::rpc::service::task_service::BatchServiceImpl;
 use risingwave_batch::task::{BatchEnvironment, BatchManager};
 use risingwave_common::config::{
-    load_config, AsyncStackTraceOption, MAX_CONNECTION_WINDOW_SIZE, STREAM_WINDOW_SIZE,
+    load_config, AsyncStackTraceOption, StorageConfig, MAX_CONNECTION_WINDOW_SIZE,
+    STREAM_WINDOW_SIZE,
 };
 use risingwave_common::monitor::process_linux::monitor_process;
 use risingwave_common::util::addr::HostAddr;
@@ -52,7 +54,9 @@ use risingwave_stream::task::{LocalStreamManager, StreamEnvironment};
 use tokio::sync::oneshot::Sender;
 use tokio::task::JoinHandle;
 
-use crate::memory_management::memory_manager::GlobalMemoryManager;
+use crate::memory_management::memory_manager::{
+    GlobalMemoryManager, MIN_COMPUTE_MEMORY_MB, SYSTEM_RESERVED_MEMORY_MB,
+};
 use crate::rpc::service::config_service::ConfigServiceImpl;
 use crate::rpc::service::exchange_metrics::ExchangeServiceMetrics;
 use crate::rpc::service::exchange_service::ExchangeServiceImpl;
@@ -71,11 +75,13 @@ pub async fn compute_node_serve(
 ) -> (Vec<JoinHandle<()>>, Sender<()>) {
     // Load the configuration.
     let config = load_config(&opts.config_path, Some(opts.override_config));
+    validate_compute_node_memory_config(opts.total_memory_bytes, &config.storage);
     info!(
         "Starting compute node with config {:?} with debug assertions {}",
         config,
         if cfg!(debug_assertions) { "on" } else { "off" }
     );
+
     // Initialize all the configs
     let storage_config = Arc::new(config.storage.clone());
     let stream_config = Arc::new(config.streaming.clone());
@@ -144,12 +150,8 @@ pub async fn compute_node_serve(
     let mut extra_info_sources: Vec<ExtraInfoSourceRef> = vec![];
     if let Some(storage) = state_store.as_hummock_trait() {
         extra_info_sources.push(storage.sstable_id_manager().clone());
-        // Note: we treat `hummock+memory-shared` as a shared storage, so we won't start the
-        // compactor along with compute node.
-        if config.storage.state_store == "hummock+memory"
-            || config.storage.state_store.starts_with("hummock+disk")
-            || storage_config.disable_remote_compactor
-        {
+
+        if storage_config.embedded_compactor_enabled() {
             tracing::info!("start embedded compactor");
             let read_memory_limiter = Arc::new(MemoryLimiter::new(
                 storage_config.compactor_memory_limit_mb as u64 * 1024 * 1024 / 2,
@@ -325,3 +327,28 @@ pub async fn compute_node_serve(
 
     (join_handle_vec, shutdown_send)
 }
+
+/// Check whether the compute node has enough memory to perform computing tasks. Apart from storage,
+/// it must reserve at least `MIN_COMPUTE_MEMORY_MB` for computing and `SYSTEM_RESERVED_MEMORY_MB`
+/// for other system usage. Otherwise, it is not allowed to start.
+fn validate_compute_node_memory_config(
+    cn_total_memory_bytes: usize,
+    storage_config: &StorageConfig,
+) {
+    let storage_memory_mb = storage_config.total_storage_memory_limit_mb();
+    if storage_memory_mb << 20 > cn_total_memory_bytes {
+        panic!(
+            "The storage memory exceeds the total compute node memory:\nTotal compute node memory: {}\nStorage memory: {}\nAt least 1 GB memory should be reserved apart from the storage memory. Please increase the total compute node memory or decrease the storage memory in configurations and restart the compute node.", 
+            convert(cn_total_memory_bytes as _),
+            convert((storage_memory_mb << 20) as _)
+        );
+    } else if (storage_memory_mb + MIN_COMPUTE_MEMORY_MB + SYSTEM_RESERVED_MEMORY_MB) << 20
+        >= cn_total_memory_bytes
+    {
+        panic!(
+            "No enough memory for computing and other system usage:\nTotal compute node memory: {}\nStorage memory: {}\nAt least 1 GB memory should be reserved apart from the storage memory. Please increase the total compute node memory or decrease the storage memory in configurations and restart the compute node.",
+            convert(cn_total_memory_bytes as _),
+            convert((storage_memory_mb << 20) as _)
+        );
+    }
+}

src/storage/src/hummock/event_handler/hummock_event_handler.rs

@@ -54,7 +54,7 @@ pub struct BufferTracker {
 
 impl BufferTracker {
     pub fn from_storage_config(config: &StorageConfig) -> Self {
-        let capacity = config.shared_buffer_capacity_mb as usize * (1 << 20);
+        let capacity = config.shared_buffer_capacity_mb * (1 << 20);
         let flush_threshold = capacity * 4 / 5;
         Self::new(capacity, flush_threshold)
     }