diff --git a/src/client/src/client_manager.rs b/src/client/src/client_manager.rs
index 3acb8b3d8f..6b7771a36b 100644
--- a/src/client/src/client_manager.rs
+++ b/src/client/src/client_manager.rs
@@ -23,6 +23,8 @@ use moka::future::{Cache, CacheBuilder};
 
 use crate::Client;
 
+const DEFAULT_TIMEOUT: Duration = Duration::from_secs(10);
+
 pub struct DatanodeClients {
     channel_manager: ChannelManager,
     clients: Cache<Peer, Client>,
@@ -31,7 +33,9 @@ pub struct DatanodeClients {
 
 impl Default for DatanodeClients {
     fn default() -> Self {
-        let config = ChannelConfig::new().timeout(Duration::from_secs(8));
+        let config = ChannelConfig::new()
+            .timeout(DEFAULT_TIMEOUT)
+            .connect_timeout(DEFAULT_TIMEOUT);
 
         Self {
             channel_manager: ChannelManager::with_config(config),
diff --git a/src/meta-srv/src/mocks.rs b/src/meta-srv/src/mocks.rs
index c6c38fbbdf..df901c5ea4 100644
--- a/src/meta-srv/src/mocks.rs
+++ b/src/meta-srv/src/mocks.rs
@@ -96,8 +96,8 @@ pub async fn mock(
     });
 
     let config = ChannelConfig::new()
-        .timeout(Duration::from_secs(1))
-        .connect_timeout(Duration::from_secs(1))
+        .timeout(Duration::from_secs(10))
+        .connect_timeout(Duration::from_secs(10))
         .tcp_nodelay(true);
     let channel_manager = ChannelManager::with_config(config);
 
diff --git a/src/storage/src/flush.rs b/src/storage/src/flush.rs
index 901d7c2851..ebb41d7af9 100644
--- a/src/storage/src/flush.rs
+++ b/src/storage/src/flush.rs
@@ -253,9 +253,9 @@ impl<S: LogStore> FlushJob<S> {
         let region_id = self.shared.id();
         let mut futures = Vec::with_capacity(self.memtables.len());
         let iter_ctx = IterContext {
-            for_flush: true,
             // TODO(ruihang): dynamic row group size based on content (#412)
             batch_size: WRITE_ROW_GROUP_SIZE,
+            // All sequences are visible by default.
             ..Default::default()
         };
 
diff --git a/src/storage/src/memtable.rs b/src/storage/src/memtable.rs
index d89e06dcb0..b76af906ad 100644
--- a/src/storage/src/memtable.rs
+++ b/src/storage/src/memtable.rs
@@ -99,11 +99,6 @@ pub struct IterContext {
     /// Max visible sequence (inclusive).
     pub visible_sequence: SequenceNumber,
 
-    // TODO(yingwen): [flush] Maybe delay deduping and visiblility handling, just returns all rows
-    // in memtable.
-    /// Returns all rows, ignores sequence visibility and key duplication.
-    pub for_flush: bool,
-
     /// Schema the reader expect to read.
     ///
     /// Set to `None` to read all columns.
@@ -119,7 +114,6 @@ impl Default for IterContext {
             batch_size: consts::READ_BATCH_SIZE,
             // All data in memory is visible by default.
             visible_sequence: SequenceNumber::MAX,
-            for_flush: false,
             projected_schema: None,
             time_range: None,
         }
diff --git a/src/storage/src/memtable/btree.rs b/src/storage/src/memtable/btree.rs
index 949d2c67c3..c067eef293 100644
--- a/src/storage/src/memtable/btree.rs
+++ b/src/storage/src/memtable/btree.rs
@@ -238,12 +238,8 @@ impl BTreeIterator {
             map.range(..)
         };
 
-        let (keys, sequences, op_types, values) = if self.ctx.for_flush {
-            collect_iter(iter, self.ctx.batch_size)
-        } else {
-            let iter = MapIterWrapper::new(iter, self.ctx.visible_sequence, self.ctx.time_range);
-            collect_iter(iter, self.ctx.batch_size)
-        };
+        let iter = MapIterWrapper::new(iter, self.ctx.visible_sequence, self.ctx.time_range);
+        let (keys, sequences, op_types, values) = collect_iter(iter, self.ctx.batch_size);
 
         if keys.is_empty() {
             return Ok(None);
diff --git a/src/storage/src/memtable/tests.rs b/src/storage/src/memtable/tests.rs
index 83f97a8503..df7a639aac 100644
--- a/src/storage/src/memtable/tests.rs
+++ b/src/storage/src/memtable/tests.rs
@@ -267,6 +267,12 @@ fn write_iter_memtable_case(ctx: &TestContext) {
     }
 }
 
+#[test]
+fn test_iter_context_default() {
+    let ctx = IterContext::default();
+    assert_eq!(SequenceNumber::MAX, ctx.visible_sequence);
+}
+
 #[test]
 fn test_write_iter_memtable() {
     let tester = MemtableTester::default();
@@ -435,7 +441,6 @@ fn test_sequence_visibility() {
             let iter_ctx = IterContext {
                 batch_size: 1,
                 visible_sequence: 9,
-                for_flush: false,
                 projected_schema: None,
                 time_range: None,
             };
@@ -454,7 +459,6 @@ fn test_sequence_visibility() {
             let iter_ctx = IterContext {
                 batch_size: 1,
                 visible_sequence: 10,
-                for_flush: false,
                 projected_schema: None,
                 time_range: None,
             };
@@ -473,7 +477,6 @@ fn test_sequence_visibility() {
             let iter_ctx = IterContext {
                 batch_size: 1,
                 visible_sequence: 11,
-                for_flush: false,
                 projected_schema: None,
                 time_range: None,
             };