应用内存升高原因排查
起因 最近一个部署了 go 应用的服务器出现了 OOM 的现象，内存占用过高。 原因 通过 Pyroscope 分析得出是因为 Minio 的 go sdk 中的 PutObject 函数占用了大量的内存。 Pyroscope 是什么，前面的文章已经介绍过了，这里就不过多介绍了。 接下来我们通过查看相关的源码来查看是什么原因。 // PutObject creates an object in a bucket. // // You must have WRITE permissions on a bucket to create an object. // // - For size smaller than 16MiB PutObject automatically does a // single atomic PUT operation. // // - For size larger than 16MiB PutObject automatically does a // multipart upload operation. // // - For size input as -1 PutObject does a multipart Put operation // until input stream reaches EOF. Maximum object size that can // be uploaded through this operation will be 5TiB. // // WARNING: Passing down '-1' will use memory and these cannot // be reused for best outcomes for PutObject(), pass the size always. // // NOTE: Upon errors during upload multipart operation is entirely aborted. func (c *Client) PutObject(ctx context.Context, bucketName, objectName string, reader io.Reader, objectSize int64, opts PutObjectOptions, ) (info UploadInfo, err error) { if objectSize < 0 && opts.DisableMultipart { return UploadInfo{}, errors.New("object size must be provided with disable multipart upload") } err = opts.validate() if err != nil { return UploadInfo{}, err } return c.putObjectCommon(ctx, bucketName, objectName, reader, objectSize, opts) } 从方法的注释可以看出，当传递的大小为 -1 时，会进行多次 put 操作，直到输入流结束。 多次 put 操作的最大大小为 5TiB， 并且不能重用内存，导致占用大量内存。 ...