Block till sufficient space is available #57
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skylark/gateway/gateway_reciever.py
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| @@ -92,6 +92,12 @@ def recv_chunks(self, conn: socket.socket, addr: Tuple[str, int]): | |||
| # receive header and write data to file | |||
| chunk_header = WireProtocolHeader.from_socket(conn) | |||
| logger.debug(f"[server:{server_port}] Got chunk header {chunk_header.chunk_id}: {chunk_header}") | |||
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| # wait for free space (at least space for two chunks) | |||
| while self.chunk_store.remaining_bytes() < chunk_header.chunk_len * 2: | |||
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Something to keep in mind is that, even if you are waiting in this while loop, data received from the source gateway (or previous gateway) is still being buffered by TCP, and takes up memory in the form of the TCP receive buffer in the kernel. If this becomes a problem, we might want to have a protocol for this gateway to send a message to the previous gateway indicating that it is ready, and for the previous gateway to receive this message before starting the transfer. You wait for two chunks' worth of space already, but you have 16 connections per gateway that is sending you data, so it might be worth bumping up that constant to take this into account.
The code you have is fine for now, but if you still get out of memory problems down the road, then this might be the issue (though I'm fine waiting until this actually becomes a problem before fixing this).
commit a6ad91b Merge: 5106140 e616614 Author: Paras Jain <[email protected]> Date: Sun Jan 16 00:33:20 2022 -0800 Merge branch 'main' into dev/paras/block_2.0 commit 5106140 Author: Paras Jain <[email protected]> Date: Sun Jan 16 05:10:18 2022 +0000 Fixed version of block for free space (fixing #57)
commit a6ad91b Merge: 5106140 e616614 Author: Paras Jain <[email protected]> Date: Sun Jan 16 00:33:20 2022 -0800 Merge branch 'main' into dev/paras/block_2.0 commit 5106140 Author: Paras Jain <[email protected]> Date: Sun Jan 16 05:10:18 2022 +0000 Fixed version of block for free space (fixing #57)
Enables running gateways on instances with less RAM such as Azure.