get_jstat_output
Execute jstat commands to monitor JVM performance metrics like garbage collection, class loading, and compiler statistics for Java processes.
Instructions
执行 jstat 监控命令
Args:
pid (str): 进程ID，使用字符串形式（如："12345"）
option (Optional[str]): jstat选项，如gc、class、compiler等
interval (str): 采样间隔（毫秒），使用字符串形式（如："1000"表示1秒）
count (str): 采样次数，使用字符串形式（如："10"）
Returns:
Dict: 包含jstat执行结果的字典，包含以下字段：
- raw_output (str): 原始输出
- timestamp (float): 时间戳
- success (bool): 是否成功
- error (Optional[str]): 错误信息
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| pid | No | ||
| option | No | ||
| interval | No | ||
| count | No |
Implementation Reference
- src/jvm_mcp_server/server.py:635-683 (handler)Main handler function for the 'get_jstat_output' MCP tool. Validates inputs (PID, interval, count), executes JstatCommand via the executor, and formats the response dictionary with raw output, success status, and error handling.
@self.mcp.tool() def get_jstat_output(pid: str = "", option: Optional[str] = None, interval: str = "", count: str = "") -> Dict: """执行 jstat 监控命令 Args: pid (str): 进程ID，使用字符串形式（如："12345"） option (Optional[str]): jstat选项，如gc、class、compiler等 interval (str): 采样间隔（毫秒），使用字符串形式（如："1000"表示1秒） count (str): 采样次数，使用字符串形式（如："10"） Returns: Dict: 包含jstat执行结果的字典，包含以下字段： - raw_output (str): 原始输出 - timestamp (float): 时间戳 - success (bool): 是否成功 - error (Optional[str]): 错误信息 """ try: validated_pid = self._validate_and_convert_id(pid if pid else None, "process ID") if validated_pid is None: return { "raw_output": "", "timestamp": time.time(), "success": False, "error": "Invalid process ID" } validated_interval = self._validate_and_convert_id(interval if interval else None, "interval") validated_count = self._validate_and_convert_id(count if count else None, "count") except ValueError as e: return { "raw_output": "", "timestamp": time.time(), "success": False, "error": str(e) } cmd = JstatCommand(self.executor, JstatFormatter()) result = cmd.execute(str(validated_pid), option=option, interval=validated_interval, count=validated_count) return { "raw_output": result.get('output', ''), "timestamp": time.time(), "success": result.get('success', False), "error": result.get('error') } - Helper classes JstatCommand and JstatFormatter. JstatCommand constructs the jstat command line (jstat -option pid [interval [count]]). JstatFormatter formats the command result into a simple dictionary with success, output/error, and metadata.
class JstatCommand(BaseCommand): """Jstat命令实现""" def __init__(self, executor, formatter): super().__init__(executor, formatter) self.timeout = 30 def get_command( self, pid: str, option: Optional[str] = None, interval: Optional[int] = None, count: Optional[int] = None, *args, **kwargs) -> str: # option: gc, gccapacity, class, compiler, util, ... cmd = f'jstat' if option: cmd += f' -{option}' cmd += f' {pid}' if interval is not None: cmd += f' {interval}' if count is not None: cmd += f' {count}' return cmd class JstatFormatter(OutputFormatter): """Jstat输出格式化器（仅文本输出）""" def format(self, result: CommandResult) -> Dict[str, Any]: if not result.success: return { "success": False, "error": result.error, "timestamp": result.timestamp.isoformat() } return { "success": True, "output": result.output, "execution_time": result.execution_time, "timestamp": result.timestamp.isoformat() }