第一眼看到这个错误是不是就觉的是磁盘满了呢，但是df看怎么都没有100%占用的。没错，原始的感觉是对的，但是分叉路不对，习惯了df -h，就忘记了inode这东西，因为它也会满，所以要双管齐下 先df -h查看磁盘文件大小占用的空间，有则清理 如果df -h查看磁盘未满，就df -i 查看inode占用比例，如果满也是清理 不过inode清理需要找到是哪里占用了，不像du -hs一样能从上往下查到 […]
mysql java使用示例
简单的更容易遗忘，除非持久化输出
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import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; public class MysqlDemo { static { try { Class.forName("com.mysql.cj.jdbc.Driver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } } public static void run_test(String url, String user, String pwd){ try { System.out.println(String.format("url: %s", url)); Connection conn = DriverManager.getConnection(url, user, pwd); Statement stmt1 = conn.createStatement(); ResultSet rs; rs = stmt1.executeQuery("show tables"); while(rs.next()){ System.out.println(rs.getString(1)); } //持续插入数据 int rows=0; stmt1.executeUpdate("drop database if exists jdbc_test"); stmt1.executeUpdate("create database jdbc_test"); stmt1.executeUpdate("create table jdbc_test.tb_jdbc(id bigint key, c1 varchar(128))"); for(int i=1;i<1000;i++){ String val = String.format("(%d, 'jdbc_abc_%d')", i, i); rows = stmt1.executeUpdate("replace into jdbc_test.tb_jdbc(id, c1) values" + val); if(rows != 0){ System.out.println("insert " + val); } Thread.sleep(1000); } }catch (Exception e) { System.out.println(e.toString()); } } public static void main(String[] args){ run_test(args[0], args[1], args[2]); } } |
在idea中创建一个普通的项目，编译后打包输出成mysql_jdbc_demo.jar文件，然后这么执行 java -cp mysql-connector-java8.jar:mysql_jdbc_demo.jar MysqlDemo "jdbc:mysql://192.168.2.199:3306 […]
mysql c-api使用示例
整理旧资料，收拾新东西，有些db状态不是mysql客户端能模拟出来的，所以记录下打样过程，如果以后有需要也不用从头看起
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#include <stdio.h> #include <stdlib.h> #include <string.h> #include <mysql/mysql.h> MYSQL *conn; void print_err() { fprintf(stderr, "%d %s", mysql_errno(conn),mysql_error(conn)); } void init_db() { conn = mysql_init(NULL); if(conn == NULL) { fprintf(stderr, "mysql_init() failed"); exit(EXIT_FAILURE); } mysql_real_connect(conn, "192.168.1.10", "test1234", "test1234", "db1", 3306, NULL, 0); } void query(char* sql, char* param1) { int ret = -1; MYSQL_STMT *stmt; MYSQL_BIND bind[1]; long length; stmt = mysql_stmt_init(conn); if(conn == NULL) { fprintf(stderr, "mysql_stmt_init() failed\n"); exit(EXIT_FAILURE); } ret = mysql_stmt_prepare(stmt, sql, strlen(sql)); if(ret != 0) { fprintf(stderr, "mysql_stmt_prepare() failed\n"); print_err(); exit(EXIT_FAILURE); mysql_stmt_execute(stmt); }else{ fprintf(stdout, "mysql_stmt_prepare() success\n"); } if(mysql_stmt_reset(stmt)) { fprintf(stderr, "mysql_stmt_reset() failed\n"); print_err(); }else{ fprintf(stdout, "mysql_stmt_reset() success\n"); } ret = mysql_stmt_prepare(stmt, sql, strlen(sql)); if(ret != 0) { fprintf(stderr, "mysql_stmt_prepare() failed\n"); print_err(); exit(EXIT_FAILURE); mysql_stmt_execute(stmt); }else{ fprintf(stdout, "mysql_stmt_prepare() success\n"); } memset(bind, 0, sizeof(bind)); /*普通bind*/ bind[0].buffer_type = MYSQL_TYPE_STRING; bind[0].buffer = (char *)param1; bind[0].buffer_length = strlen(param1); ret = mysql_stmt_bind_param(stmt, bind); if(ret != 0) { fprintf(stderr, "mysql_stmt_bind_param() failed\n"); exit(EXIT_FAILURE); mysql_stmt_execute(stmt); }else{ fprintf(stdout, "mysql_stmt_bind_param() success\n"); } /*发送long data*/ // bind[0].buffer_type= MYSQL_TYPE_STRING; // bind[0].length= &length; // bind[0].is_null= 0; // ret = mysql_stmt_bind_named_param(stmt, bind, 1, NULL); // if(ret != 0) // { // fprintf(stderr, "mysql_stmt_bind_named_param() failed\n"); // print_err(); // }else{ // fprintf(stdout, "mysql_stmt_bind_named_param() success\n"); // } if(mysql_stmt_send_long_data(stmt,0,"MySQL",5)) { fprintf(stderr, "mysql_stmt_send_long_data() failed\n"); print_err(); }else{ fprintf(stdout, "mysql_stmt_send_long_data() success\n"); } if(mysql_stmt_send_long_data(stmt,0," - The most popular Open Source database",40)) { fprintf(stderr, "mysql_stmt_send_long_data() failed\n"); print_err(); }else{ fprintf(stdout, "mysql_stmt_send_long_data() success\n"); } /***/ ret = mysql_stmt_execute(stmt); if(ret != 0) { fprintf(stderr, "mysql_stmt_execute() failed\n"); print_err(); }else{ fprintf(stdout, "mysql_stmt_execute() success\n"); } mysql_stmt_close(stmt); } void close_db() { mysql_close(conn); } int main() { init_db(); query("select md5(?) from dual", "123"); close_db(); } /* gcc -o foo mysql_c_demo.c -I/home/mysql8/mysql8.0.22_run/include -L/home/mysql8/mysql8.0.22_run/lib -lmysqlclient */ |
mysql odbc-bench
很久没有更新了，每天七七八八的琐碎事情占据了所有时间，是不是该暂停一下了 1，安装好unixODBC，安装完之后通过odbcinst -j查看配置文件路径，如下实例
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# odbcinst -j unixODBC 2.3.7 DRIVERS............: /usr/local/etc/odbcinst.ini SYSTEM DATA SOURCES: /usr/local/etc/odbc.ini FILE DATA SOURCES..: /usr/local/etc/ODBCDataSources USER DATA SOURCES..: /root/.odbc.ini SQLULEN Size.......: 8 SQLLEN Size........: 8 SQLSETPOSIROW Size.: 8 # cat /usr/local/etc/odbcinst.ini [MYSQL] Description = ODBC for MySQL Driver = /usr/lib/libmyodbc5w.so Setup = /usr/lib/libodbcmyS.so Driver64 = /usr/lib64/libmyodbc5w.so Setup64 = /usr/lib64/libodbcmyS.so FileUsage = 1 # cat /usr/local/etc/odbc.ini [tpcc2] Description = MySQL test database Driver = MYSQL SERVER = 10.21.12.235 USER = test1234 PASSWORD = test1234 PORT = 15051 DATABASE = tpcc2 TraceFile = /tmp/odbc.trace Trace = ON |
2，构建和使用odbc-bench git路径是这个https://github.com/openlink/odbc-bench [crayon-6792 […]
shell统计日志中的时间戳差值
比如这样的日志，需要统计后一条记录和前一条记录之间的时间差值 [2024-10-11 10:42:24 023047] DEBUG 478832,readermgn.cpp:17:run,tid:0x7f80697fa700,479378,reader mgn running [2024-10-11 10:42:30 329273] DEBUG 478832,readermgn.cpp:17:ru […]
python下的数据库连接池dbutils
最近在测试业务的时候，出现长时间并发线程跑sql的时候建立链接耗时的问题，于是搜罗了一下python下是否有链接池的功能，于是乎找到dbutils这个模块，官方路径是在这里 https://webwareforpython.github.io/DBUtils/ 基础使用相对不麻烦，使用pymysql作为连接器进行演示验证
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#coding: utf-8 import pymysql from dbutils.pooled_db import PooledDB import threading from concurrent.futures import ThreadPoolExecutor pool = PooledDB( creator=pymysql, maxconnections=16, # 可同时创建的最大连接数，如果并发很快这里可能会出现超过最大链接数的报错 mincached=4, maxcached=12, maxshared=128, blocking=False, maxusage=None, setsession=["set autocommit=0"], #用于设置session的前导语句 ping=1, reset=True, # mysql登陆参数 host="192.30.2.19", port=3306, user="test1234", passwd="test1234", database="mysql", charset="utf8mb4", cursorclass=pymysql.cursors.DictCursor, # 这里设置返回cursor类型, DictCursor会返回字典类型，带有字段名 ) def run_test(num): tid = threading.currentThread().ident conn = pool.connection() cursor = conn.cursor() cursor.execute("begin") cursor.execute(f"insert into db1.t1(id,tid) values({num}, '{tid}')") cursor.execute(f"select {num} as num, '{tid}' as tid from dual") print(cursor.fetchall()) cursor.execute("commit") conn.close() for i in range(30): # 每次最多创建16个线程 threadpool = ThreadPoolExecutor(16) for j in range(16): threadpool.submit(run_test, *(i*16 + j,)) threadpool.shutdown(wait=True) |
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docker部署elasticsearch和kibana
1、下载官网镜像 因为要在外网隔离环境部署，所以需要将image下载后再搬迁过去 docker pull docker.elastic.co/elasticsearch/elasticsearch:8.14.2 docker pull docker.elastic.co/kibana/kibana:8.14.2 docker image ls docker save da0e65225d10 -o […]
jconsole远程链接
虚虚实实 仅记录一下使用方法，往往复复，也不会经常使用到了 加上下面的启动参数运行jar包 /opt/TencentKona-21.0.3.b1/bin/java -jar -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=9527 -Dcom.sun.management.jmxremote.rmi.port=9 […]