在Debian系统上使用Node.js时,查找日志中的慢查询可以通过以下步骤实现:
fs
)模块按行读取日志文件。可以通过前端选择的日志查找时间和精确度来进行查找。以下是一个简单的Node.js脚本示例,用于读取和过滤日志文件:
const fs = require('fs');
const readline = require('readline');
function readLog(date, type, operation) {
const logPath = `appDirName/log/ivsvr_${date}.log`;
const logStr = '';
fs.stat(logPath, function (err, stats) {
if (err) {
console.log('无日志信息可供查看');
return;
}
let lineCount = 0;
const fReadName = logPath;
const fRead = fs.createReadStream(fReadName);
const objReadline = readline.createInterface({ input: fRead });
objReadline.on('line', (line) => {
const itemStr = line.trim();
const time = itemStr.slice(0, 19);
const content = itemStr.substr(20);
if (!time || !content) return;
lineCount++;
switch (type) {
case '0': // 查找所有日志
break;
case '1': // 按小时过滤
if (time.slice(0, 2) === hour) {
matched = true;
} else {
matched = false;
}
break;
case '2': // 按分钟过滤
if (time.slice(0, 5) === minute) {
matched = true;
} else {
matched = false;
}
break;
case '3': // 按秒过滤
if (time.slice(0, 8) === second) {
matched = true;
} else {
matched = false;
}
break;
default:
console.log('unknown type!');
break;
}
if (matched && lineCount <= logReadFlag) {
const itemArr = itemStr.split(' ');
const logDate = itemArr[0];
const logTime = itemArr[1];
const result = itemArr[2];
if (result === 'err') {
const operation = itemArr[4];
result = `失败: ${itemArr[5]} (${itemArr[6] || ''})`;
} else {
const operation = itemArr[4] + ' ' + itemArr[5](itemArr[6] || '');
result = '成功';
}
logStr += `<tr><td>${logTime}</td><td>${operation}</td><td>${result}</td></tr>`;
}
});
objReadline.on('close', () => {
if (lineCount <= logReadFlag && logStr) {
console.log(logStr);
} else if (logReadFlag === 0 && logStr) {
console.log('刷新成功,更新了' + lineCount + '条日志!');
} else {
console.log('刷新成功,无日志更新!');
}
});
});
}
// 示例调用
readLog(new Date().toISOString().slice(0, 10), '1', 'search');
请注意,上述代码仅为示例,实际应用中可能需要根据具体的日志格式和需求进行调整。此外,为了提高性能,可以考虑使用流式处理和异步操作来处理大型日志文件。