NodeJS

Background To obtain more relevant metrics and a comprehensive understanding of traces when external API requests access our systems, We opted to enable tracing for the network mesh components situated above the Kubernetes service. This specifically covers the entire request flow from its initiation: the ingress gateway receives the request and routes it according to defined rules to a particular K8s service; then, the Istio sidecar proxy containers, running alongside our application containers in the same pod, receive and proxy the request to main containers, where our Node.js server process ultimately handle it and generate the appropriate response. Before enabling tracing for istio mesh, tracing for a HTTP request began when the request reached our application container at the pod level, with HTTP auto-instrumentation serving as the trace root. ...

I was recently investigating ways to improve the efficiency of file uploads to a Node.js server. This need arose after encountering a production bug where the absence of a maximum file size limit for uploads led to an out-of-memory crash due to file buffers consuming excessive heap memory. In this Node.js server, I was using Express and express-openapi-validator to document the server’s API with an OpenAPI specification. express-openapi-validator utilizes multer for file uploads. I had previously encountered this library whenever file uploads from forms needed to be handled in Node.js, but I never questioned why a separate library was necessary for file uploads. This time, I decided to go deeper to understand if a dedicated package for file uploads is truly needed, and if so, what specific benefits Multer or similar libraries provide. I initially needed to find a configuration option in express-openapi-validator to set a request-wide limit on the maximum size (in bytes) of data allowed in a request, including all file attachments. The express-openapi-validator package offers a fileUploader configuration (fileUploader documentation) that passes options directly to multer. ...