--- title: OceanBase 数据库 V4.2.1 版本因为备份卡住导致合并卡住报错 Too Many sstables, cannot add another sstable any 的原因和解决方法-OceanBase数据库使用指南 description: 了解OceanBase数据库在实际应用中关于 OceanBase 数据库 V4.2.1 版本因为备份卡住导致合并卡住报错 Too Many sstables, cannot add another sstable any 的原因和解决方法相关的常见问题和使用技巧，帮助您快速解决 OceanBase 数据库 V4.2.1 版本因为备份卡住导致合并卡住报错 Too Many sstables, cannot add another sstable any 的原因和解决方法的难题。 --- 切换语言 - 简体中文 - English 划线反馈 # OceanBase 数据库 V4.2.1 版本因为备份卡住导致合并卡住报错 Too Many sstables, cannot add another sstable any 的原因和解决方法 更新时间：2026-05-11 09:51 适用版本： V4.0.x、V4.1.x、V4.2.x 内容类型：Troubleshoot ## 问题现象 租户卡合并，查看 `__all_virtual_dag_warning_history` 发现 MAJOR_MERGE 报错 OB_SIZE_OVERFLOW，并且存在很久之前 module 为 BACKUP 的任务。 ```shell MySQL [oceanbase]> select * from __all_virtual_dag_warning_history where tenant_id=1002; +---------------+----------+-----------+-----------------------------------+------------+----------------------+---------------------------------+---------+----------------------------+----------------------------+-----------+----------------------------------------------------------------------------------------------------------------------------------+ | svr_ip | svr_port | tenant_id | task_id | module | type | ret | status | gmt_create | gmt_modified | retry_cnt | warning_info | +---------------+----------+-----------+-----------------------------------+------------+----------------------+---------------------------------+---------+----------------------------+----------------------------+-----------+----------------------------------------------------------------------------------------------------------------------------------+ | xxx.xxx.xxx.160 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | BACKUP | PREFETCH_BACKUP_INFO | OB_OSS_ERROR | WARNING | 2024-05-13 13:32:28.483716 | 2024-05-13 13:32:28.483716 | 0 | info="DAG_PREFETCH_BACKUP_INFO";tenant_id=1002;backup_set_id=244;backup_data_type=2;ls_id=1001;turn_id=1;retry_id=14;task_id=2; | | xxx.xxx.xxx.160 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | BACKUP | BACKUP_DATA | OB_OSS_ERROR | WARNING | 2024-05-13 15:32:45.892451 | 2024-05-13 15:32:45.892451 | 0 | info="DAG_BACKUP_DATA";tenant_id=1002;backup_set_id=244;backup_data_type=2;ls_id=1001;turn_id=1;retry_id=18;task_id=5; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | BACKUP | PREFETCH_BACKUP_INFO | OB_OSS_ERROR | WARNING | 2024-05-13 11:31:21.155562 | 2024-05-13 11:31:21.155562 | 0 | info="DAG_PREFETCH_BACKUP_INFO";tenant_id=1002;backup_set_id=244;backup_data_type=2;ls_id=1001;turn_id=1;retry_id=0;task_id=116; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | BACKUP | PREFETCH_BACKUP_INFO | OB_OSS_ERROR | WARNING | 2024-05-13 11:51:52.892445 | 2024-05-13 11:51:52.892445 | 0 | info="DAG_PREFETCH_BACKUP_INFO";tenant_id=1002;backup_set_id=244;backup_data_type=2;ls_id=1001;turn_id=1;retry_id=3;task_id=0; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | BACKUP | PREFETCH_BACKUP_INFO | OB_BACKUP_MAJOR_NOT_COVER_MINOR | WARNING | 2024-09-19 15:13:26.035467 | 2024-09-19 15:13:26.035467 | 0 | info="DAG_PREFETCH_BACKUP_INFO";tenant_id=1002;backup_set_id=304;backup_data_type=2;ls_id=1001;turn_id=1;retry_id=0;task_id=114; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:05:43.665832 | 2024-09-20 14:32:39.611969 | 1092 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207447;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:06:20.253585 | 2024-09-20 14:32:39.801456 | 1092 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207445;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:07:43.587289 | 2024-09-20 14:32:40.533494 | 1092 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207450;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:07:49.163709 | 2024-09-20 14:32:41.415234 | 1092 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207451;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:07:37.161357 | 2024-09-20 14:32:41.594973 | 1090 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207448;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:07:40.274592 | 2024-09-20 14:32:42.065449 | 1090 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207446;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:10:18.698726 | 2024-09-20 14:32:42.068798 | 1089 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207449;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | | xxx.xxx.xxx.161 | 2882 | 1002 | xxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | COMPACTION | MAJOR_MERGE | OB_SIZE_OVERFLOW | RETRYED | 2024-09-19 02:10:35.532628 | 2024-09-20 14:32:42.289718 | 1089 | info="DAG_MAJOR_MERGE";ls_id=1001;tablet_id=207444;compaction_scn=1726682401689713864;extra_info="merge_type="MEDIUM_MERGE""; | +---------------+----------+-----------+-----------------------------------+------------+----------------------+---------------------------------+---------+----------------------------+----------------------------+-----------+----------------------------------------------------------------------------------------------------------------------------------+ 13 rows in set (0.01 sec) ``` 日志报错 `Too Many sstables, cannot add another sstable any more`。 ## 关键信息 关键日志信息中出现含有 `Too Many sstables, cannot add another sstable any more`、`tablet multi version start not advance for a long time` 内容，可以确认遇到了 Too many sstable 导致卡转储、卡合并的问题。 ```shell observer.log.20240920120623366:[2024-09-20 12:00:40.261715] WDIAG [STORAGE] check_ready_for_read (ob_tablet_table_store.cpp:1599) [57654][T1002_MAJOR_MER][T1002][xxxxx-xxxxx-xxxxx-xxxxx] [lt=10][errcode=-4019] Too Many sstables, cannot add another sstable any more(ret=-4019, this={this:0x7efa34c266e0, version:257, major_tables:{cnt:129, is_inited:true}, minor_tables:{cnt:0, is_inited:false}, ddl_sstables:{cnt:0, is_inited:false}, meta_major_tables:{cnt:0, is_inited:false}, memtables:{count:0}, is_ready_for_read:false, sstable_arrays:{major_tables:{{i:0, addr:388350493-1567367-0-2305855460324012032-0, type:"MAJOR", tablet_id:{id:207444} ``` 当同时打印 `tablet multi version start not advance for a long time` 时，`min_medium_snapshot` 为备份卡住的时间，可以与 `__all_virtual_dag_warning_history` 表的 BACKUP 任务创建时间对应。 ![iamge](https://obbusiness-private.oss-cn-shanghai.aliyuncs.com/doc/img/knowledge-base/database/backup-and-restore/20250208toomanysstables.png) ## 问题原因 问题发生时备份任务卡住很久，tablet 计算多版本保留点时需要考虑 `tablet min medium snapshot` 位点。由于备份任务 hold 着一个 4 个月前的 `tablet handle`，从 mds data 上读到的 `min medium snapshot` 是 4 个月前的，进而导致多版本保留点一直停留在 4 个月前，大量旧版本的 MAJOR 无法回收，最终导致 SSTable 数量达到上限。SSTable 数量达到上限后，无法进行转储生成新的 SSTable，导致合并卡住。 ## 问题的风险及影响 租户合并卡住，对应的表无法转储，严重的可能会发生租户 MemStore 内存占用 100% 发生停写。 ## 影响租户 影响 OceanBase 数据库中的 SYS 租户和 Oracle 租户以及 MySQL 租户。 ## 适用版本 OceanBase 数据库 V4.x 版本。 ## 解决方法及规避方式 - 解决方法： 停止备份；若存在残留备份任务，重启残留备份任务节点。 - 规避方式： 保证备份介质的稳定性，避免备份功能出现异常。 Previous [启用二次备份失败的问题](https://www.oceanbase.com/knowledge-base/oceanbase-database-1000000000297644) Next [备份时产生日志告警 backup file appender is not closed 的原因和解决方法](https://www.oceanbase.com/knowledge-base/oceanbase-database-1000000001944496) ![有帮助](https://gw.alipayobjects.com/mdn/ob_asset/afts/img/A*y6ocSqN8cqsAAAAAAAAAAAAAARQnAQ)![无帮助](https://gw.alipayobjects.com/mdn/ob_asset/afts/img/A*BG9IQJyLHF8AAAAAAAAAAAAAARQnAQ)![反馈](https://gw.alipayobjects.com/mdn/ob_asset/afts/img/A*eTWdQKCRKHwAAAAAAAAAAAAAARQnAQ)[AI](https://www.oceanbase.com/obi) 咨询热线