Use
when MySQL inserts a large amount of data and needs to compare and duplicate Db($table)-> where($where)-> find();
In this case, an error will be reported: sqlstate [08004] [1040] too many connections
This is mainly due to too many database connections
resolvent:
Introduce DB class
use think\Db;
The query statement is changed to:
Db::table($table)-> where($where)-> find();
That’s it
Problem description
When there are multiple instances of a micro service in the Nacos registry, click an instance to go offline and report an error
caused: errCode: 500, errMsg: do metadata operation failed ;
caused: com.alibaba.nacos.consistency.exception.ConsistencyException: com.alibaba.nacos.core.distributed.raft.exception.NoLeaderException: The Raft Group [naming_instance_metadata] did not find the Leader node;
caused: com.alibaba.nacos.core.distributed.raft.exception.NoLeaderException: The Raft Group [naming_instance_metadata] did not find the Leader node;
Solution
Nacos uses the raft algorithm to calculate the leader and will record the cluster address started last time. Therefore, when the IP address of our own server changes (especially the students started locally when we study, because sometimes our network environment will change… WiFi, so the IP address often changes), the cluster address recorded by raft will become invalid, If there is a problem with the selected leader, just delete the protocol folder under the data folder under the root directory of Nacos.
The reason is that the history mode is used HTML5 history mode | Vue router
I didn’t find a solution
So we changed the routing to hash mode
I use cli3
It was
import {createRouter, createWebHistory} from 'vue-router'
const router = createRouter({
history: createWebHistory(process.env.BASE_URL),
routes
})Change to
import {createRouter, createWebHashHistory} from 'vue-router'
const router = createRouter({
model:'hash',
history: createWebHashHistory(),
routes
})It’s normal after modification
Vs2019 + QT parses the XML file and reports an error at doc.setcontent
Made a very low-level mistake. Record the process.
A QT project was established long ago. Now to add a function of parsing XML files using the qdom class, there is always an error in the sentence doc.setcontent (& amp; file) , and there is no error message. The relevant C + + codes are as follows:
QString error;
int line, column;
if (doc.setContent(&file, &error, &line, &column)) {
qDebug() << doc.toString(4);
}
else {
qDebug() << "Error:" << error << "in line " << line << "column" << column;
}
file.close();
When doc.setcontent (& amp; file, & amp; error, & amp; line, & amp; column) , critical error detected c00000374 is displayed
The first reaction is that the XML file is incorrectly written. For example, there is no space in the space, Chinese punctuation is entered, or the two sides of the tag are inconsistent
after repeatedly confirming that the XML file is correct, the stackoverflow search said that the relative path cannot be used, but the absolute path must be used… Another attempt of the absolute path is useless.
Create a new project and run it with the same code without error. Through careful comparison, it is found that in the new project, I added the XML class library
but not in the original project!
So far, add $(qtdir) \ include \ qtxml in the C/C + + include directory, add qt5xmld.lib [debug mode] and qt5xml. Lib [release mode] in the linker, and the operation is successful!
Finally, I found that if the XML file is written incorrectly, the above program can locate the error location. Direct reporting of fatal error/critical error or unresolved external symbols like this__ declspec(dllimport) public: __ Cdecl , the probability is that the Lib file link is wrong rather than the code problem. You need to check whether the environment is configured correctly.
A simple question has been wordy for a long time… Mainly to warn yourself that you must think more and think more about ways to expose the problem when you encounter a problem that has no solution on the Internet!
Error reporting result:
When the project is running, a compilation error occurs suddenly and the dependency cannot be found. Follow the prompt to execute NPM install — save Vue editor bridge, or an error is reported
This dependency was not found:
* vue-editor-bridge in ./node_modules/cache-loader/dist/cjs.js??ref--12-0!./node_modules/babel-loader/lib!./node_modules/cache-loader/dist/cjs.js??ref--0-0!./node_modules/vue-loader/lib??vue-loader-options!./src/components/Test.vue?vue&type=script&lang=js&
To install it, you can run: npm install --save vue-editor-bridge
Error from chokidar (C:\): Error: EBUSY: resource busy or locked, lstat 'C:\DumpStack.log.tmp'
Cause finding:
After finding similar error reports, it is found that vscode automatically adds a line of import, as if it entered func when entering function, and vscode imported func as a component by default (you don’t have to be so smart?)
import func from 'vue-temp/vue-editor-bridge'
Solution:
Just delete this line of code
1. Exception description
org.springframework.transaction.TransactionSystemException: Could not commit JDBC transaction; nested exception is java.sql.SQLException: Write conflict, txnStartTS=426985930345676879,
After switching the tidb database, the above error reports occur from time to time;
2. Problem analysis
It is found that there is a write conflict by searching the online data according to the error content. The optimistic lock is used by default under version 3.0 of tidb database. This problem will occur in the case of multiple concurrent modifications;
3. Solution
(1) Add & amp; database connection; sessionVariables=tidb_ txn_ Change mode = pessimistic to pessimistic lock
(2) Break big things apart
4. Subsequent optimization selection
Known configuration
ndk.dir=/home/.../Sdk/ndk-bundle
sdk.dir=/home/.../Sdk
Gradlew compilation error
Execution failed for task ':app:transformNativeLibsWithStripDebugSymbolForxxxxx'.
> A problem occurred starting process 'command '\
<sdk.dir>/ndk-bundle/toolchains/mips64el-linux-android-4.9/prebuilt/linux-x86_64/bin/mips64el-linux-android-strip''
View Android/SDK installation path
$ ll <sdk.dir>/ndk-bundle/toolchains/
drwxrwxrwx 3 lily lily 4096 aarch64-linux-android-4.9/
drwxrwxrwx 3 lily lily 4096 arm-linux-androideabi-4.9/
drwxrwxrwx 3 lily lily 4096 llvm/
lrwxrwxrwx 1 lily lily 25 mips64el-linux-android-4.9 -> aarch64-linux-android-4.9/
lrwxrwxrwx 1 lily lily 25 mipsel-linux-android-4.9 -> arm-linux-androideabi-4.9/
drwxrwxrwx 3 lily lily 4096 renderscript/
drwxrwxrwx 3 lily lily 4096 x86-4.9/
drwxrwxrwx 3 lily lily 4096 x86_64-4.9/
I downloaded an extra version of NDK R15, android-ndk-r15c
To change to
$ ll <sdk.dir>/ndk-bundle/toolchains/
drwxrwxrwx 3 lily lily 4096 aarch64-linux-android-4.9/
drwxrwxrwx 3 lily lily 4096 arm-linux-androideabi-4.9/
drwxrwxrwx 3 lily lily 4096 llvm/
lrwxrwxrwx 1 lily lily 84 mips64el-linux-android-4.9 -> <sdk.dir>/ndk/android-ndk-r15c/toolchains/mips64el-linux-android-4.9/
lrwxrwxrwx 1 lily lily 82 mipsel-linux-android-4.9 -> <sdk.dir>/ndk/android-ndk-r15c/toolchains/mipsel-linux-android-4.9/
drwxrwxrwx 3 lily lily 4096 renderscript/
drwxrwxrwx 3 lily lily 4096 x86-4.9/
drwxrwxrwx 3 lily lily 4096 x86_64-4.9/
In this way, there is no error in compilation
No toolchains found in the NDK toolchains folder for ABI with prefix
1、 Mybatisplus only configures mapper in YML, and the path scanning is not enough
mapper-locations: classpath:com/jack/shale_porosity/mapper/xml/*.xml
In this way, only the basemapper provided by mybatis can be used. The mapper file is not loaded in the target file.
2、 Configure the mapper file scanning path again in the pom.xml file
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
In this way, you can successfully use custom SQL and SQL in basemapper.
The springboot integration CXF calls WebService and reports an error:
javax.wsdl.WSDLException: WSDLException: faultCode=PARSER_ ERROR: java.lang.RuntimeException: Cannot create a secure XMLInputFactory。
As shown below:
The final reason is that wstx-asl-3.2.6.jar package is introduced into the project. This package is the same as many classes of woodstox-core-asl-4.4.1.jar, resulting in jar package conflict.
Solution steps:
1. View Maven dependencies:
mvn dependency:tree
Package structure comparison:
2. Maven dependency excludes wstx-asl-3.2.6.jar package dependency
Find the location where the dependency is introduced and exclude wstx ASL:
Reference document: WebService problem, urgent- CSDN forum WebService problem, urgent!!! https://bbs.csdn.net/topics/390491260
Port out of range: – 1 for Tomcat startup in idea
The reason for this may be that the port number of your configuration file is – 1
how to solve it
first, let’s find the configuration file in conf under your Tomcat installation path
Mine is here
Open with Notepad
Change the port number to another number at this position. Make it larger. Here I change it to 1001
OK, it’s normal
0. std::__1::system_error::system_error(std::__1::error_code, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) @ 0x158ebc6f in ?
1. ?@ 0x1587f49f in ?
2. ?@ 0x1587eeb6 in ?
3. ?@ 0x1587d018 in ?
4. std::__1::__fs::filesystem::directory_iterator::directory_iterator(std::__1::__fs::filesystem::path const&, std::__1::error_code*, std::__1::__fs::filesystem::directory_options) @ 0x1587ce40 in ?
5. DB::DiskLocalDirectoryIterator::DiskLocalDirectoryIterator(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) @ 0xfee57cf in /usr/bin/clickhouse
6. DB::DiskLocal::iterateDirectory(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) @ 0xfedffc5 in /usr/bin/clickhouse
7. DB::MergeTreeIndexGranularityInfo::getMarksExtensionFromFilesystem(std::__1::shared_ptr<DB::IDisk> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) @ 0x10d84f8d in /usr/bin/clickhouse
8. DB::MergeTreeData::createPart(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, DB::MergeTreePartInfo const&, std::__1::shared_ptr<DB::IVolume> const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, DB::IMergeTreeDataPart const*) const @ 0x10ca13c0 in /usr/bin/clickhouse
9. ?@ 0x10cdf50d in /usr/bin/clickhouse
10. ThreadPoolImpl<ThreadFromGlobalPool>::worker(std::__1::__list_iterator<ThreadFromGlobalPool, void*>) @ 0x8fd8f18 in /usr/bin/clickhouse
11. ThreadFromGlobalPool::ThreadFromGlobalPool<void ThreadPoolImpl<ThreadFromGlobalPool>::scheduleImpl<void>(std::__1::function<void ()>, int, std::__1::optional<unsigned long>)::'lambda0'()>(void&&, void ThreadPoolImpl<ThreadFromGlobalPool>::scheduleImpl<void>(std::__1::function<void ()>, int, std::__1::optional<unsigned long>)::'lambda0'()&&...)::'lambda'()::operator()() @ 0x8fdaabf in /usr/bin/clickhouse
12. ThreadPoolImpl<std::__1::thread>::worker(std::__1::__list_iterator<std::__1::thread, void*>) @ 0x8fd61ff in /usr/bin/clickhouse
13. ?@ 0x8fd9ae3 in /usr/bin/clickhouse
14. start_thread @ 0x7ea5 in /usr/lib64/libpthread-2.17.so
15. clone @ 0xfe9fd in /usr/lib64/libc-2.17.so
Cannot print extra info for Poco::Exception (version 21.8.4.51 (official build))
2021.09.18 10:46:22.375009 [ 16809 ] {} <Error> Application: filesystem error: in directory_iterator::directory_iterator(...): Structure needs cleaning [/var/lib/clickhouse/store/61d/61d588d9-1562-4435-a1d5-88d91562a435/202109_84030_84496_322/]The error log indicates that the directory should be deleted, but the directory cannot be deleted. Just remove the directory to another directory and start it again
Reason: the reason for this is activity_ The layout in main.xml conflicts with the code written in mainactivity.java
Solution: check the conflicts in the code and change the conflicting parts to be consistent.