http_body example is not working with large body

[manXcoder]

I tried to capture the full request body as shown in the example, but the last chunk of data is always missing.
The total body size is 73,072 bytes, but I can only receive 65,500 bytes — the last 7,572 bytes are lost.

Eventually, I worked around this by make a custom cache to store each chunk in on_http_request_body till the _end_of_stream is true.

The full istio log：
2025-08-11T03:14:52.856058Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1898 [Tags: "ConnectionId":"611224"] Http2Visitor::OnFrameHeader(3, 16375, 0, 0) thread=22
2025-08-11T03:14:52.856063Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1950 [Tags: "ConnectionId":"611224"] Http2Visitor::OnBeginDataForStream(3, 16375) thread=22
2025-08-11T03:14:52.856066Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1962 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 16375, end_stream: false thread=22
2025-08-11T03:14:52.856073Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1991 [Tags: "ConnectionId":"611224"] Http2Visitor dispatching DATA for stream 3 thread=22
2025-08-11T03:14:52.858477Z debug envoy router external/envoy/source/common/router/router.cc:738 [Tags: "ConnectionId":"611224","StreamId":"841103180158735629"] router decoding headers:
2025-08-11T03:14:52.858509Z debug envoy router external/envoy/source/common/router/upstream_request.cc:588 [Tags: "ConnectionId":"611224","StreamId":"841103180158735629"] pool ready thread=22
2025-08-11T03:14:52.895524Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1898 [Tags: "ConnectionId":"611224"] Http2Visitor::OnFrameHeader(3, 16375, 0, 0) thread=22
2025-08-11T03:14:52.895555Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1950 [Tags: "ConnectionId":"611224"] Http2Visitor::OnBeginDataForStream(3, 16375) thread=22
2025-08-11T03:14:52.895559Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1962 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 16375, end_stream: false thread=22
2025-08-11T03:14:52.895567Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1991 [Tags: "ConnectionId":"611224"] Http2Visitor dispatching DATA for stream 3 thread=22
2025-08-11T03:14:52.895659Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1898 [Tags: "ConnectionId":"611224"] Http2Visitor::OnFrameHeader(3, 16375, 0, 0) thread=22
2025-08-11T03:14:52.895666Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1950 [Tags: "ConnectionId":"611224"] Http2Visitor::OnBeginDataForStream(3, 16375) thread=22
2025-08-11T03:14:52.895669Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1962 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 16375, end_stream: false thread=22
2025-08-11T03:14:52.895674Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1991 [Tags: "ConnectionId":"611224"] Http2Visitor dispatching DATA for stream 3 thread=22
2025-08-11T03:14:52.934725Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1898 [Tags: "ConnectionId":"611224"] Http2Visitor::OnFrameHeader(3, 16375, 0, 0) thread=22
2025-08-11T03:14:52.934749Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1950 [Tags: "ConnectionId":"611224"] Http2Visitor::OnBeginDataForStream(3, 16375) thread=22
2025-08-11T03:14:52.934753Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1962 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 16375, end_stream: false thread=22
2025-08-11T03:14:52.934759Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1991 [Tags: "ConnectionId":"611224"] Http2Visitor dispatching DATA for stream 3 thread=22
2025-08-11T03:14:52.934828Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1898 [Tags: "ConnectionId":"611224"] Http2Visitor::OnFrameHeader(3, 7572, 0, 1) thread=22
2025-08-11T03:14:52.934832Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1950 [Tags: "ConnectionId":"611224"] Http2Visitor::OnBeginDataForStream(3, 7572) thread=22
2025-08-11T03:14:52.934834Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1962 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 7572, end_stream: true thread=22
2025-08-11T03:14:52.934838Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:1998 [Tags: "ConnectionId":"611224"] Http2Visitor: remaining data payload: 0, end_stream: true thread=22
2025-08-11T03:14:52.934842Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:2003 [Tags: "ConnectionId":"611224"] Http2Visitor::OnEndStream(3) thread=22
2025-08-11T03:14:52.934846Z debug envoy http2 external/envoy/source/common/http/http2/codec_impl.cc:2008 [Tags: "ConnectionId":"611224"] Http2Visitor dispatching DATA for stream 3 thread=22
2025-08-11T03:14:52.934852Z debug envoy http external/envoy/source/common/http/conn_manager_impl.cc:1130 [Tags: "ConnectionId":"611224","StreamId":"841103180158735629"] request end stream thread=22