fix(grpc): return bool if mempool is out of sync instead of returning… (

#6728)

… an error

Removed the error "Mempool out of sync, blockchain db advanced passed
current tip in mempool storage;" when getting a block template and
instead return a bool that indicates such.

The clients that are worried about this can check the flag and request a
new template, while clients that are not worried about this can accept
the data for what it is

applications/minotari_app_grpc/proto/block.proto

@@ -134,5 +134,8 @@ message NewBlockTemplate {
     // This flag indicates if the inputs, outputs and kernels have been sorted internally, that is, the sort() method
     // has been called. This may be false even if all components are sorted.
     AggregateBody body = 2;
+    // Sometimes the mempool has not synced to the latest tip, this flag indicates if the mempool is out of sync.
+    // In most cases the next call to get_new_block_template will return a block with the mempool in sync.
+    bool is_mempool_in_sync = 3;
 }
 

applications/minotari_app_grpc/src/conversions/new_block_template.rs

@@ -68,6 +68,7 @@ impl TryFrom<NewBlockTemplate> for grpc::NewBlockTemplate {
                     .collect(),
             }),
             header: Some(header),
+            is_mempool_in_sync: block.is_mempool_in_sync,
         })
     }
 }
@@ -105,6 +106,7 @@ impl TryFrom<grpc::NewBlockTemplate> for NewBlockTemplate {
             target_difficulty: Default::default(),
             reward: Default::default(),
             total_fees: Default::default(),
+            is_mempool_in_sync: block.is_mempool_in_sync,
         })
     }
 }

applications/minotari_merge_mining_proxy/src/block_template_protocol.rs

@@ -250,7 +250,15 @@ impl BlockTemplateProtocol<'_> {
         let (block_template_with_coinbase, height) = match block_templates.get_new_template(best_block_hash).await {
             None => {
                 let new_template = match self.get_new_block_template().await {
-                    Ok(val) => val,
+                    Ok(val) => {
+                        if !val.template.is_mempool_in_sync {
+                            error!(target: LOG_TARGET, "Mempool is not in sync. Retrying to get new block template (try {})", loop_count);
+                            return Err(MmProxyError::FailedToGetBlockTemplate(
+                                "mempool not in sync".to_string(),
+                            ));
+                        }
+                        val
+                    },
                     Err(err) => {
                         error!(target: LOG_TARGET, "grpc get_new_block_template ({})", err.to_string());
                         return Err(err);

base_layer/core/src/base_node/comms_interface/inbound_handlers.rs

@@ -258,18 +258,15 @@ where B: BlockchainBackend + 'static
             NodeCommsRequest::GetNewBlockTemplate(request) => {
                 let best_block_header = self.blockchain_db.fetch_tip_header().await?;
                 let last_seen_hash = self.mempool.get_last_seen_hash().await?;
+                let mut is_mempool_synced = true;
                 if last_seen_hash != FixedHash::default() && best_block_header.hash() != &last_seen_hash {
                     warn!(
                         target: LOG_TARGET,
                         "Mempool out of sync - last seen hash '{}' does not match the tip hash '{}'. This condition \
                          should auto correct with the next block template request",
                         last_seen_hash, best_block_header.hash()
                     );
-                    return Err(CommsInterfaceError::InternalError(
-                        "Mempool out of sync, blockchain db advanced passed current tip in mempool storage; this \
-                         should auto correct with the next block template request"
-                            .to_string(),
-                    ));
+                    is_mempool_synced = false;
                 }
                 let mut header = BlockHeader::from_previous(best_block_header.header());
                 let constants = self.consensus_manager.consensus_constants(header.height);
@@ -313,6 +310,7 @@ where B: BlockchainBackend + 'static
                     self.get_target_difficulty_for_next_block(request.algo, constants, prev_hash)
                         .await?,
                     self.consensus_manager.get_block_reward_at(height),
+                    is_mempool_synced,
                 )?;
 
                 debug!(target: LOG_TARGET,

base_layer/core/src/blocks/new_block_template.rs

@@ -51,13 +51,17 @@ pub struct NewBlockTemplate {
     pub reward: MicroMinotari,
     /// The total fees is the sum of all the fees in the block.
     pub total_fees: MicroMinotari,
+    /// Sometimes the mempool has not synced to the latest tip, this flag indicates if the mempool is out of sync.
+    /// In most cases the next call to get_new_block_template will return a block with the mempool in sync.
+    pub is_mempool_in_sync: bool,
 }
 
 impl NewBlockTemplate {
     pub fn from_block(
         block: Block,
         target_difficulty: Difficulty,
         reward: MicroMinotari,
+        is_mempool_in_sync: bool,
     ) -> Result<Self, TransactionError> {
         let Block { header, body } = block;
         let total_fees = body.get_total_fee()?;
@@ -67,6 +71,7 @@ impl NewBlockTemplate {
             target_difficulty,
             reward,
             total_fees,
+            is_mempool_in_sync,
         })
     }
 }

base_layer/core/src/chain_storage/tests/blockchain_database.rs

@@ -441,7 +441,8 @@ mod prepare_new_block {
     fn it_errors_for_genesis_block() {
         let db = setup();
         let genesis = db.fetch_block(0, true).unwrap();
-        let template = NewBlockTemplate::from_block(genesis.block().clone(), Difficulty::min(), 5000 * T).unwrap();
+        let template =
+            NewBlockTemplate::from_block(genesis.block().clone(), Difficulty::min(), 5000 * T, true).unwrap();
         let err = db.prepare_new_block(template).unwrap_err();
         assert!(matches!(err, ChainStorageError::InvalidArguments { .. }));
     }
@@ -452,7 +453,7 @@ mod prepare_new_block {
         let genesis = db.fetch_block(0, true).unwrap();
         let next_block = BlockHeader::from_previous(genesis.header());
         let mut template =
-            NewBlockTemplate::from_block(next_block.into_builder().build(), Difficulty::min(), 5000 * T).unwrap();
+            NewBlockTemplate::from_block(next_block.into_builder().build(), Difficulty::min(), 5000 * T, true).unwrap();
         // This would cause a panic if the sanity checks were not there
         template.header.height = 100;
         let err = db.prepare_new_block(template.clone()).unwrap_err();
@@ -468,7 +469,7 @@ mod prepare_new_block {
         let genesis = db.fetch_block(0, true).unwrap();
         let next_block = BlockHeader::from_previous(genesis.header());
         let template =
-            NewBlockTemplate::from_block(next_block.into_builder().build(), Difficulty::min(), 5000 * T).unwrap();
+            NewBlockTemplate::from_block(next_block.into_builder().build(), Difficulty::min(), 5000 * T, true).unwrap();
         let block = db.prepare_new_block(template).unwrap();
         assert_eq!(block.header.height, 1);
     }

base_layer/core/tests/helpers/block_builders.rs

@@ -149,6 +149,7 @@ async fn genesis_template(
         header.into_builder().with_coinbase_utxo(utxo, kernel).build(),
         Difficulty::min(),
         coinbase_value,
+        true,
     )
     .unwrap();
     (block, output)
@@ -315,6 +316,7 @@ pub async fn chain_block(
             .build(),
         Difficulty::min(),
         reward,
+        true,
     )
     .unwrap()
 }
@@ -339,6 +341,7 @@ pub fn chain_block_with_coinbase(
             .build(),
         achieved_difficulty.unwrap_or(Difficulty::min()),
         consensus.get_block_reward_at(height),
+        true,
     )
     .unwrap()
 }
@@ -377,6 +380,7 @@ pub async fn chain_block_with_new_coinbase(
             .build(),
         Difficulty::min(),
         reward,
+        true,
     )
     .unwrap();
     (template, coinbase_output)

base_layer/core/tests/helpers/database.rs

@@ -59,6 +59,7 @@ pub async fn create_orphan_block(
             .build(),
         Difficulty::min(),
         coinbase_value,
+        true,
     )
     .unwrap();
     Block::new(template.header.into(), template.body)

base_layer/core/tests/tests/block_validation.rs

@@ -1351,6 +1351,7 @@ async fn test_fee_overflow() {
             .build(),
         Difficulty::min(),
         consensus_manager.get_block_reward_at(height),
+        true,
     );
     assert!(template_result.is_err());
     assert_eq!(

base_layer/tari_mining_helper_ffi/src/lib.rs

@@ -804,7 +804,7 @@ mod tests {
             let error_ptr = &mut error as *mut c_int;
             let header = BlockHeader::new(0);
             let block =
-                NewBlockTemplate::from_block(header.into_builder().build(), Difficulty::min(), 0.into()).unwrap();
+                NewBlockTemplate::from_block(header.into_builder().build(), Difficulty::min(), 0.into(), true).unwrap();
 
             let block_bytes = borsh::to_vec(&block).unwrap();
             #[allow(clippy::cast_possible_truncation)]