[fix](log) Support fe log rollover size strategy (#34446)

fe/fe-common/src/main/java/org/apache/doris/common/Config.java

@@ -2599,6 +2599,12 @@ public class Config extends ConfigBase {
     //==========================================================================
     //                    begin of cloud config
     //==========================================================================
+    @ConfField(description = {"是否启用FE 日志文件按照大小删除策略，当日志大小超过指定大小，删除相关的log。默认为按照时间策略删除",
+        "Whether to enable the FE log file deletion policy based on size, "
+            + "where logs exceeding the specified size are deleted. "
+            + "It is disabled by default and follows a time-based deletion policy."},
+            options = {"age", "size"})
+    public static String log_rollover_strategy = "age";
 
     @ConfField public static int info_sys_accumulated_file_size = 4;
     @ConfField public static int warn_sys_accumulated_file_size = 2;