Details
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Bug
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Status: Closed (View Workflow)
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Minor
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Resolution: Fixed
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10.2.2, 10.3.0
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linux
Description
Somewhere between 10.1 and 10.2, some of the IO statistics in 'show engine innodb status' stopped working.
In 10.1:
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
in 10.2:
Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] ,
ibuf aio reads:, log i/o's:, sync i/o's:
As you can see there are some zeroes missing.
thanks
Jonathan
Attachments
Issue Links
- relates to
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MDEV-16264 Implement a common work queue for InnoDB background tasks
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- Closed
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Activity
| Field | Original Value | New Value |
|---|---|---|
| Description |
Somewhere between 10.1 and 10.2, some of the IO statistics in 'show engine innodb status' stopped working.
In 10.1: {{Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] , ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0 }} in 10.2: {{Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] , ibuf aio reads:, log i/o's:, sync i/o's: }} As you can see there are some zeroes missing. thanks Jonathan |
Somewhere between 10.1 and 10.2, some of the IO statistics in 'show engine innodb status' stopped working.
In 10.1: {quote}Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] , ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0{quote} in 10.2: {{Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] , ibuf aio reads:, log i/o's:, sync i/o's: }} As you can see there are some zeroes missing. thanks Jonathan |
| Description |
Somewhere between 10.1 and 10.2, some of the IO statistics in 'show engine innodb status' stopped working.
In 10.1: {quote}Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] , ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0{quote} in 10.2: {{Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] , ibuf aio reads:, log i/o's:, sync i/o's: }} As you can see there are some zeroes missing. thanks Jonathan |
Somewhere between 10.1 and 10.2, some of the IO statistics in 'show engine innodb status' stopped working.
In 10.1: {quote}Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] , ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0{quote} in 10.2: {quote}Pending normal aio reads: [0, 0, 0, 0] , aio writes: [0, 0, 0, 0] , ibuf aio reads:, log i/o's:, sync i/o's:{quote} As you can see there are some zeroes missing. thanks Jonathan |
| Affects Version/s | 10.2.12 [ 22810 ] |
| Fix Version/s | 10.2 [ 14601 ] | |
| Assignee | Marko Mäkelä [ marko ] |
| Labels | upstream |
| Status | Open [ 1 ] | Confirmed [ 10101 ] |
| Affects Version/s | 10.3.0 [ 22127 ] | |
| Affects Version/s | 10.2.2 [ 22013 ] | |
| Affects Version/s | 10.2 [ 14601 ] | |
| Affects Version/s | 10.2.12 [ 22810 ] |
| Fix Version/s | 10.3 [ 22126 ] |
| Fix Version/s | 10.4 [ 22408 ] |
| Link |
This issue relates to |
It looks like this got broken further in MDEV-16264 (10.5.0). We now have totally useless output in os_aio_print(), which I will remove:
diff --git a/storage/innobase/os/os0file.cc b/storage/innobase/os/os0file.cc
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index fc3da454d2d..48d7c69319f 100644
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--- a/storage/innobase/os/os0file.cc
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+++ b/storage/innobase/os/os0file.cc
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@@ -4160,10 +4160,6 @@ os_aio_print(FILE* file)
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time_t current_time;
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double time_elapsed;
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- fputs("Pending normal aio reads:", file);
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- putc('\n', file);
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current_time = time(NULL);
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time_elapsed = 0.001 + difftime(current_time, os_last_printout);
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As part of MDEV-16264, other output (along with class AIO) was already removed in MariaDB Server 10.5.0.
Because there have not been any further votes or comments for this issue, I think that it is fine to remove the code.
Asynchronous reads are only used by read-ahead. Asynchronous writes are being used for data file pages, and it could hurt performance to accurately track the number of pending operations, which is not interesting anyway. I suspect that the output had originally been added in order to be able to diagnose some hangs. I do not remember any I/O hangs lately.
| Status | Confirmed [ 10101 ] | In Progress [ 3 ] |
Most of the statistics were already removed in MariaDB 10.5.0. 10.5.10 will remove the string "Pending normal aio reads" that was not followed by any numbers.
| issue.field.resolutiondate | 2021-04-26 12:48:42.0 | 2021-04-26 12:48:42.956 |
| Fix Version/s | 10.5.10 [ 25204 ] | |
| Fix Version/s | 10.2 [ 14601 ] | |
| Fix Version/s | 10.3 [ 22126 ] | |
| Fix Version/s | 10.4 [ 22408 ] | |
| Resolution | Fixed [ 1 ] | |
| Status | In Progress [ 3 ] | Closed [ 6 ] |
| Workflow | MariaDB v3 [ 86338 ] | MariaDB v4 [ 154076 ] |
The same issue appears to exist in MySQL since version 5.7.8, where some code was refactored. Either the function AIO::print_segment_info() or its caller should display m_n_reserved.