本文主要介绍 OceanBase 数据库中租户资源统计项及其查询方法。
适用版本
OceanBase 数据库 V4.1.x、V4.2.x 版本。
CPU 资源统计项
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逻辑 CPU 使用率（线程处理请求的时间占比）。
通过虚拟表
__all_virtual_sysstat在 SYS 系统租户下，查看租户的cpu_usage，表示一段时间内（1s）租户工作线程的处理请求时间占比和租户unit规格，粗算的逻辑 CPU 使用率，数值代表百分比，例如 400 指的是 400%。obclient> SELECT * FROM oceanbase.__all_virtual_sysstat WHERE tenant_id = 1 AND name = 'cpu usage';输出结果如下：
+-----------+--------------+----------+------------+-------+------------+---------+-----------+-------+-------------+ | tenant_id | svr_ip | svr_port | statistic# | value | value_type | stat_id | name | class | can_visible | +-----------+--------------+----------+------------+-------+------------+---------+-----------+-------+-------------+ | 1 | xx.xxx.xx.xx | 57234 | 573 | 10 | SET_VALUE | 140006 | cpu usage | 64 | 1 | +-----------+--------------+----------+------------+-------+------------+---------+-----------+-------+-------------+ -
租户线程消耗的 CPU 总时间。
通过虚拟表
__all_virtual_sysstat在 SYS 系统租户下，查看租户的cpu_time，不管是否开启cgroup，都能获取到 cpu time 的值。区别在于开启了cgroup后，会通过cgroup功能从cpuacct.usage中获取 CPU 时间；否则，不开启cgroup。只会通过 /proc/$pid/task/$tid/stat 目录来读取 CPU 时间。obclient> SELECT * FROM oceanbase.__all_virtual_sysstat WHERE tenant_id = 1 AND name = 'cpu time';输出结果如下：
+-----------+--------------+----------+------------+-------+------------+---------+----------+-------+-------------+ | tenant_id | svr_ip | svr_port | statistic# | value | value_type | stat_id | name | class | can_visible | +-----------+--------------+----------+------------+-------+------------+---------+----------+-------+-------------+ | 1 | xx.xxx.xx.xx | 57234 | 580 | 0 | SET_VALUE | 140013 | cpu time | 64 | 1 | +-----------+--------------+----------+------------+-------+------------+---------+----------+-------+-------------+
内存资源统计项
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mod 内存占用情况。
通过虚拟表
__all_virtual_memory_info在 SYS 系统租户下，查询租户的每个mod_name的内存占用情况。obclient> SELECT * FROM oceanbase.__all_virtual_memory_info WHERE tenant_id = 1 LIMIT 1;输出结果如下：
+-----------+--------------+----------+--------+-----------------+----------------+----------+--------+-----------------+-------+-----------+-----------+-------+ | tenant_id | svr_ip | svr_port | ctx_id | label | ctx_name | mod_type | mod_id | mod_name | zone | hold | used | count | +-----------+--------------+----------+--------+-----------------+----------------+----------+--------+-----------------+-------+-----------+-----------+-------+ | 1 | xx.xxx.xx.xx | 57234 | 0 | MysqlRequesReco | DEFAULT_CTX_ID | user | 0 | MysqlRequesReco | zone1 | 146604032 | 146551808 | 33 | +-----------+--------------+----------+--------+-----------------+----------------+----------+--------+-----------------+-------+-----------+-----------+-------+有关 mod 详细信息参见：V$OB_MEMORY 。
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ctx 和 mod 相关的内存信息。
通过
observer.log文件中包含 [MEMORY] 标签的日志，可以查看租户 ctx 和 mod 相关的内存信息，10 秒一次。grep "\[MEMORY\]" observer.log*输出结果如下：
observer.log.20230203145702002:[MEMORY] tenant_id= 1001 ctx_id= DEFAULT_CTX_ID hold= 374,960,128 used= 337,967,264 limit= 9,223,372,036,854,775,807 observer.log.20230203145702002:[MEMORY] idle_size= 0 free_size= 0 observer.log.20230203145702002:[MEMORY] wash_related_chunks= 0 washed_blocks= 0 washed_size= 0 observer.log.20230203145702002:[MEMORY] hold= 100,143,104 used= 100,086,048 count= 37 avg_used= 2,705,028 block_cnt= 37 chunk_cnt= 37 mod=IoControl observer.log.20230203145702002:[MEMORY] hold= 80,019,456 used= 80,000,000 count= 1 avg_used= 80,000,000 block_cnt= 1 chunk_cnt= 1 mod=MysqlRequesReco observer.log.20230203145702002:[MEMORY] hold= 41,963,520 used= 41,943,040 count= 1 avg_used= 41,943,040 block_cnt= 1 chunk_cnt= 1 mod=LogGroupBuffer observer.log.20230203145702002:[MEMORY] hold= 18,878,080 used= 17,829,440 count= 129 avg_used= 138,212 block_cnt= 129 chunk_cnt= 12 mod=SqlDtl observer.log.20230203145702002:[MEMORY] hold= 16,039,936 used= 16,000,000 count= 2 avg_used= 8,000,000 block_cnt= 2 chunk_cnt= 2 mod=SqlPlanManger
IO 资源统计项
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IO 日志信息有以下几类。
通过不同的 grep 命令查看。
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grep "[IO STATUS]" 查看所有租户不同 group 的实时 iops 值（对应
__all_virtual_io_quota表），有 IO 流量的情况下每秒打印一次。 -
grep "IO STATUS SENDER" 查看 IO 请求的调度信息，包括所有调度线程中排队的IO请求数量和下一个请求发出时间（对应
__all_virtual_io_scheduler表），每秒打印一次。 -
grep "IO STATUS TRACER" 查看 IO 引用计数统计，用以排查内存泄漏问题（前提是开了 io_trace 配置项），如果
req_count持续上涨那么可能存在有泄漏的问题，可以通过backtrace查看调用栈。示例。
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IO 统计信息的表主要是
__all_virtual_io_quota表，这个表中实时展示了不同 group 的 iops 情况。
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IO 调度信息的表主要是
__all_virtual_io_scheduler表这个表中展示了当前 IO 请求排队和调度信息，包括下一个请求的发送时间。
Session 会话信息统计项
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租户 session 会话信息。
通过查询
__all_virtual_session_info表，在 SYS 系统租户下，查看租户 session 会话信息。SELECT * FROM oceanbase.__all_virtual_session_info WHERE tenant = 'sys' LIMIT 1;输出结果如下：
+------------+------+--------+--------------------+-----------+---------+----------------------------------+------+--------+---------------------------------------------------------------------+--------------+----------+----------+--------------+---------------+----------------+-----------+----------+-----------+------------+------------------------------------+-----------+-----------+-------------+ | id | user | tenant | host | db | command | sql_id | time | state | info | svr_ip | svr_port | sql_port | proxy_sessid | master_sessid | user_client_ip | user_host | trans_id | thread_id | ssl_cipher | trace_id | ref_count | backtrace | trans_state | +------------+------+--------+--------------------+-----------+---------+----------------------------------+------+--------+---------------------------------------------------------------------+--------------+----------+----------+--------------+---------------+----------------+-----------+----------+-----------+------------+------------------------------------+-----------+-----------+-------------+ | 3221487625 | root | sys | xx.xxx.xx.xx:xxxxx | oceanbase | Query | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx | 0 | ACTIVE | select * from __all_virtual_session_info where tenant='sys' limit 1 | xx.xxx.xx.xx | 57234 | 57235 | NULL | NULL | xx.xxx.xx.xx | % | 0 | 117243 | NULL | xxxxxxxxxxxxx-xxxxxxxxxxxxxxxx-x-x | 0 | | | +------------+------+--------+--------------------+-----------+---------+----------------------------------+------+--------+---------------------------------------------------------------------+--------------+----------+----------+--------------+---------------+----------------+-----------+----------+-----------+------------+------------------------------------+-----------+-----------+-------------+ -
租户会话统计数据。
通过查询
__all_virtual_sesstat表，在 SYS 系统租户下，查看租户会话统计数据。SELECT * FROM oceanbase.__all_virtual_sesstat WHERE tenant_id = 1 LIMIT 1;输出结果如下：
+------------+--------------+----------+------------+-----------+-------+-------------+ | session_id | svr_ip | svr_port | statistic# | tenant_id | value | can_visible | +------------+--------------+----------+------------+-----------+-------+-------------+ | 3221225472 | xx.xxx.xx.xx | 57234 | 0 | 1 | 1 | 1 | +------------+--------------+----------+------------+-----------+-------+-------------+ -
租户 session 会话等待情况。
通过查询
__all_virtual_session_wait表，在 SYS 系统租户下，查看租户 session 会话等待情况。SELECT * FROM oceanbase.__all_virtual_session_wait WHERE tenant_id = 1 LIMIT 1;输出结果如下：
+------------+--------------+----------+-----------+----------+--------+-----+--------+-----+--------+----+-------+---------------+-------------+------------+-------------------+-----------------+----------------------+----------------------------+ | session_id | svr_ip | svr_port | tenant_id | event | p1text | p1 | p2text | p2 | p3text | p3 | level | wait_class_id | wait_class# | wait_class | state | wait_time_micro | time_remaining_micro | time_since_last_wait_micro | +------------+--------------+----------+-----------+----------+--------+-----+--------+-----+--------+----+-------+---------------+-------------+------------+-------------------+-----------------+----------------------+----------------------------+ | 3221225472 | xx.xxx.xx.xx | 57234 | 1 | sync rpc | pcode | 257 | size | 286 | | 0 | 0 | 107 | 7 | NETWORK | WAITED KNOWN TIME | 103613812 | NULL | 2410634833 | +------------+--------------+----------+-----------+----------+--------+-----+--------+-----+--------+----+-------+---------------+-------------+------------+-------------------+-----------------+----------------------+----------------------------+ -
租户 session 会话等待历史记录。
通过查询
__all_virtual_session_wait_history表，在 SYS 系统租户下，查看租户 session 会话等待历史记录。SELECT * FROM oceanbase.__all_virtual_session_wait_history WHERE tenant_id = 1 LIMIT 1;输出结果如下：
+------------+--------------+----------+------+-----------+--------+----------+--------+-----+--------+-----+--------+----+-------+-----------------+----------------------------+------------+ | session_id | svr_ip | svr_port | seq# | tenant_id | event# | event | p1text | p1 | p2text | p2 | p3text | p3 | level | wait_time_micro | time_since_last_wait_micro | wait_time | +------------+--------------+----------+------+-----------+--------+----------+--------+-----+--------+-----+--------+----+-------+-----------------+----------------------------+------------+ | 3221225472 | xx.xxx.xx.xx | 57234 | 1 | 1 | 20 | sync rpc | pcode | 257 | size | 286 | | 0 | 0 | 103613812 | 2442809561 | 10361.3812 | +------------+--------------+----------+------+-----------+--------+----------+--------+-----+--------+-----+--------+----+-------+-----------------+----------------------------+------------+
附录：
OceanBase 敏捷诊断工具(OceanBase Diagnostic Tool, 简称obdiag) 是一款源代码开源敏捷黑屏诊断工具，可以对OceanBase集群进行一键集群巡检、一键分析、一键根因分析以及一键诊断信息收集。
obdiag 下载地址：https://www.oceanbase.com/softwarecenter
obdiag 官方文档：https://www.oceanbase.com/docs/obdiag-cn
obdiag github地址：https://github.com/oceanbase/obdiag
obdiag SIG 文档：https://oceanbase.yuque.com/org-wiki-obtech-vh7w9r/imzr6c
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