The content of the slow log does not match the source code expectations

translator_bot · June 22, 2024, 9:57pm

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This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: slow log日志内容与源码预期不符

| username: 比特鱼-54

【TiDB Usage Environment】Production Environment
【TiDB Version】v4.0.0
【TiDashBoard Version】v4.0.0
【Reproduction Path】
【Encountered Problem: Problem Phenomenon and Impact】
How to configure so that the content formatted by the SlowLogFormat function can be fully output to the slow log file?
【Resource Configuration】
【Attachment: Screenshot/Log/Monitoring】

Where did information like KV_total and PD_total go?

translator_bot · June 22, 2024, 9:57pm

| username: 我是咖啡哥 | Original post link

It seems that there are no parameters to control formatting.
The main parameters related to slow SQL are as follows:

translator_bot · June 22, 2024, 9:57pm

| username: Jiawei | Original post link

Just a quick question: Does the source code version you are looking at match your data version? I couldn’t find this section in the 4.0.0 source code.

translator_bot · June 22, 2024, 9:57pm

| username: 比特鱼-54 | Original post link

I am looking at the release-4.0 code:

github.com

pingcap/tidb/blob/release-4.0/sessionctx/variable/session.go#L1883


      
          		}
          	}
          	if logItems.MemMax > 0 {
          		writeSlowLogItem(&buf, SlowLogMemMax, strconv.FormatInt(logItems.MemMax, 10))
          	}
          	if logItems.DiskMax > 0 {
          		writeSlowLogItem(&buf, SlowLogDiskMax, strconv.FormatInt(logItems.DiskMax, 10))
          	}
          
          	writeSlowLogItem(&buf, SlowLogPrepared, strconv.FormatBool(logItems.Prepared))
          	writeSlowLogItem(&buf, SlowLogPlanFromCache, strconv.FormatBool(logItems.PlanFromCache))
          	writeSlowLogItem(&buf, SlowLogPlanFromBinding, strconv.FormatBool(logItems.PlanFromBinding))
          	writeSlowLogItem(&buf, SlowLogHasMoreResults, strconv.FormatBool(logItems.HasMoreResults))
          	writeSlowLogItem(&buf, SlowLogKVTotal, strconv.FormatFloat(logItems.KVTotal.Seconds(), 'f', -1, 64))
          	writeSlowLogItem(&buf, SlowLogPDTotal, strconv.FormatFloat(logItems.PDTotal.Seconds(), 'f', -1, 64))
          	writeSlowLogItem(&buf, SlowLogBackoffTotal, strconv.FormatFloat(logItems.BackoffTotal.Seconds(), 'f', -1, 64))
          	writeSlowLogItem(&buf, SlowLogWriteSQLRespTotal, strconv.FormatFloat(logItems.WriteSQLRespTotal.Seconds(), 'f', -1, 64))
          	writeSlowLogItem(&buf, SlowLogSucc, strconv.FormatBool(logItems.Succ))
          	if len(logItems.Plan) != 0 {
          		writeSlowLogItem(&buf, SlowLogPlan, logItems.Plan)
          	}

Which branch are you on?

translator_bot · June 22, 2024, 9:57pm

| username: 比特鱼-54 | Original post link

Yes, that’s exactly what I find strange.
In theory, this function is responsible for formatting slow queries, so there’s no reason for it to skip the middle part.

translator_bot · June 22, 2024, 9:57pm

| username: Jiawei | Original post link

I directly pulled a 4.0.0 source code package here

translator_bot · June 22, 2024, 9:57pm

| username: Jiawei | Original post link

github.com

pingcap/tidb/blob/v4.0.0/sessionctx/variable/session.go

// Copyright 2015 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package variable

import (
	"bytes"
	"crypto/tls"
	"fmt"
	"math"

This file has been truncated. show original

This is also fine.

translator_bot · June 22, 2024, 9:57pm

| username: 比特鱼-54 | Original post link

I know what the problem is, the code version is incorrect

translator_bot · June 22, 2024, 9:57pm

| username: Jiawei | Original post link

Congratulations on successfully resolving the issue.

translator_bot · June 22, 2024, 9:57pm

| username: system | Original post link

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