diff --git a/isolated/apply-update.sh b/isolated/apply-update.sh
index 0da9c5e..4798570 100644
--- a/isolated/apply-update.sh
+++ b/isolated/apply-update.sh
@@ -136,6 +136,42 @@ contains_service() {
   return 1
 }
 
+escape_sed_replacement() {
+  local value="$1"
+  value="${value//\\/\\\\}"
+  value="${value//&/\\&}"
+  value="${value//|/\\|}"
+  printf '%s\n' "$value"
+}
+
+apply_runtime_env_defaults() {
+  local defaults_file="$SCRIPT_DIR/update-env.defaults"
+  [[ -f "$defaults_file" ]] || return 0
+
+  local backup_file line key value escaped
+  backup_file="${ENV_FILE}.bak-$(date '+%Y%m%d%H%M%S')"
+  cp "$ENV_FILE" "$backup_file"
+  log "Apply runtime env defaults: $defaults_file"
+  log "Runtime env backup: $backup_file"
+
+  while IFS= read -r line || [[ -n "$line" ]]; do
+    [[ -n "$line" ]] || continue
+    [[ "$line" == \#* ]] && continue
+    [[ "$line" == *"="* ]] || continue
+
+    key="${line%%=*}"
+    value="${line#*=}"
+    [[ "$key" =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]] || die "Invalid env key in $defaults_file: $key"
+
+    escaped="$(escape_sed_replacement "$value")"
+    if grep -q "^${key}=" "$ENV_FILE"; then
+      sed -i "s|^${key}=.*|${key}=${escaped}|" "$ENV_FILE"
+    else
+      printf '\n%s=%s\n' "$key" "$value" >> "$ENV_FILE"
+    fi
+  done < "$defaults_file"
+}
+
 need_cmd docker
 ENV_FILE="$(resolve_runtime_file "$ENV_FILE" ".env")"
 resolve_compose_files
@@ -147,6 +183,8 @@ mapfile -t UPDATE_SERVICES < <(read_services "$@")
 
 COMPOSE_CMD="$(resolve_compose_cmd)"
 
+apply_runtime_env_defaults
+
 log "Compose files: ${RESOLVED_COMPOSE_FILES[*]}"
 log "Load images: $IMAGE_TAR"
 docker load -i "$IMAGE_TAR"
diff --git a/isolated/build-update.sh b/isolated/build-update.sh
index b31840b..5866666 100644
--- a/isolated/build-update.sh
+++ b/isolated/build-update.sh
@@ -224,6 +224,11 @@ prepare_package() {
   cp "$SCRIPT_DIR/apply-update.sh" "$PACKAGE_DIR/apply-update.sh"
   chmod +x "$PACKAGE_DIR/apply-update.sh"
 
+  local profile_dir="${PROFILE_DIR:-$SCRIPT_DIR/profiles/$DEPLOY_ENV}"
+  if [[ -f "$profile_dir/update-env.defaults" ]]; then
+    cp "$profile_dir/update-env.defaults" "$PACKAGE_DIR/update-env.defaults"
+  fi
+
   local service
   for service in "${REQUESTED_SERVICES[@]}"; do
     compose_service_name "$service"
diff --git a/isolated/profiles/docker-compose.yml b/isolated/profiles/docker-compose.yml
index 2b856c1..a9673b0 100644
--- a/isolated/profiles/docker-compose.yml
+++ b/isolated/profiles/docker-compose.yml
@@ -244,12 +244,12 @@ services:
   emp-data:
     <<: *app-env
     image: ${IMAGE_NAMESPACE:-emp-test}/emp-data:${IMAGE_TAG:-latest}
-    mem_limit: ${EMP_DATA_MEM_LIMIT:-5g}
+    mem_limit: ${EMP_DATA_MEM_LIMIT:-12g}
     volumes:
       - /data/emp/logs/${IMAGE_NAMESPACE:-emp}/emp-data:/logs
     environment:
       <<: *java-file-log
-      JAVA_TOOL_OPTIONS: "${EMP_DATA_JAVA_TOOL_OPTIONS:--Xms2g -Xmx4g}"
+      JAVA_TOOL_OPTIONS: "${EMP_DATA_JAVA_TOOL_OPTIONS:--Xms4g -Xmx8g}"
       LOGGING_FILE_NAME: /logs/emp-data.log
       LOGGING_LOGBACK_ROLLINGPOLICY_FILE_NAME_PATTERN: /logs/emp-data-%d{yyyy-MM-dd}.%i.log
       SPRING_KAFKA_LISTENER_CONCURRENCY: ${EMP_DATA_KAFKA_CONCURRENCY:-10}
diff --git a/isolated/profiles/emp-uat/.env.example b/isolated/profiles/emp-uat/.env.example
index 02f4abe..175a6e0 100644
--- a/isolated/profiles/emp-uat/.env.example
+++ b/isolated/profiles/emp-uat/.env.example
@@ -52,6 +52,8 @@ KAFKA_TOPIC=YuanJing-uat-vehicle-mock-data
 KAFKA_USER=
 KAFKA_PWD=
 # emp-data Kafka listener 消费线程数，profiles/docker-compose.yml 会映射为 Spring Kafka concurrency。
+EMP_DATA_MEM_LIMIT=12g
+EMP_DATA_JAVA_TOOL_OPTIONS=-Xms4g -Xmx8g
 EMP_DATA_KAFKA_CONCURRENCY=10
 EMP_DATA_KAFKA_MAX_POLL_RECORDS=500
 
diff --git a/isolated/profiles/emp-uat/update-env.defaults b/isolated/profiles/emp-uat/update-env.defaults
new file mode 100644
index 0000000..29cc8f4
--- /dev/null
+++ b/isolated/profiles/emp-uat/update-env.defaults
@@ -0,0 +1,4 @@
+# Runtime defaults that emp-uat incremental update packages should enforce
+# before recreating services.
+EMP_DATA_MEM_LIMIT=12g
+EMP_DATA_JAVA_TOOL_OPTIONS=-Xms4g -Xmx8g