Used memory hits the high watermark(0.800000) of total system memory.

[LETMECALM]

Question: Used memory hits the high watermark(0.800000) of total system memory.
版本：3.4，会出现周期性OOM问题，请问如何解决

[Nicole00]

https://docs.nebula-graph.com.cn/3.6.0/5.configurations-and-logs/1.configurations/3.graph-config/#memory
可以修改 nebula-graphd.conf 里的这个配置，然后重启graphd
该值默认是 0.8 表示 80% ，可以改成 0.9999

[LETMECALM]

updated by wey: translated into EN

The judgment condition for the threshold is available memory divided by (total memory - reserved memory). If the available memory is still below this threshold of 0.99, it should be lowered instead of raised. Adjusting the threshold seems to be a temporary solution rather than addressing the root cause. The exception occurs when executing the match query command, while other graph-related operations work fine. Does match operation consume system memory? By default, memory_purge_enabled = true enables regular memory cleanup. Why isn't the memory space being released? This issue occurs periodically and I would appreciate an explanation.

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阈值的判断条件是 可用内存/(总内存 - 保留内存) ，改成 0.99 可用内存还是低于该阈值，应该是调低而不是调高吧，调阈值的方式应该是治标不治本吧。报该异常是进行 match query 命令是报错，其他图相关操作是正常的，match 操作会占用系统内存吗，默认开启了memory_purge_enabled = true 定期清理内存，为啥内存空间没有得到释放，这个问题是周期性出现的，望解答。

[wey-gu]

OOM

"Memory Tracker" was introduced in 3.4.0, highly recommended to leverage it to help with this.

[LETMECALM]

How to use Memory Tracker ?

[wey-gu]

How to use Memory Tracker ?

You could refer to docs and a blog post explaining about how to configure/leverage it :)

CN:

• https://docs.nebula-graph.com.cn/3.6.0/5.configurations-and-logs/1.configurations/4.storage-config/#memory_tracker
• https://discuss.nebula-graph.com.cn/t/topic/13128

EN:

• https://docs.nebula-graph.io/3.6.0/5.configurations-and-logs/1.configurations/4.storage-config/#memory_tracker_configurations
• https://www.nebula-graph.io/posts/memory-tracker-practices

[wey-gu]

Why isn't the memory space being released?

It's about storaged, not graphd, right?
There are caches(rocksDB) there, which are configurable, too(see storaged configuration docs, and rocksdb docs).

[QingZ11]

Hi, I have noticed that the issue you created hasn’t been updated for nearly a month, so I have to close it for now. If you have any new updates, you are welcome to reopen this issue anytime.

Thanks a lot for your contribution anyway 😊

[peak-xu]

OOM

"Memory Tracker" was introduced in 3.4.0, highly recommended to leverage it to help with this.

Must it be a container environment to use memory tracker？

[wey-gu]

OOM

"Memory Tracker" was introduced in 3.4.0, highly recommended to leverage it to help with this.

Must it be a container environment to use memory tracker？

no , it's supported on both container and bare metal.