Memory leak with rest/block REST endpoint and getblock RPC when verbosity >=2 #30052

1. 
   achow101 commented at 5:53 pm on May 6, 2024: member

   Is there an existing issue for this?

   • I have searched the existing issues

   Current behaviour

   Reported in https://bitcointalk.org/index.php?topic=5495435.msg64037741#msg64037741

   When using either the rest/block endpoint or the getblock rpc with verbosity >=2, there appears to be a memory leak. Memory usage goes up ~100 MB for each call.

   The original reporter is repeatedly hitting the rest endpoint and eventually OOM’ing.

   Expected behaviour

   Memory should be freed after a response is sent, or be capped at some point to prevent an OOM.

   Steps to reproduce

   Observe bitcoind memory usage in top. Do getblock <blockhash> 2 and observe the memory usage increase. It fairly reliably reproduces, but does not always occur. Different blocks seem to have different effects, and repeating a block does not always increase usage.

   Relevant log output

   No response

   How did you obtain Bitcoin Core

   Compiled from source

   What version of Bitcoin Core are you using?

   v27.99.0-eb0bdbdd753b

   Operating system and version

   Arch

   Machine specifications

   No response

2. 
   maflcko commented at 6:14 am on May 7, 2024: member

   Is this a duplicate of #25229 (comment) ?
3. 
   maflcko commented at 6:16 am on May 7, 2024: member

   Related #24542 ?
4. 
   willcl-ark commented at 6:44 pm on May 7, 2024: member

   I could not reproduce an OOM, although I did observe resource usage increasing a little before eventually plateauing.

   I measured resident set size using python’s psutil module, whilst making 2500 REST requests for random blocks in the blockchain between block 0 and 842460. The node was in blocksonly mode, and had no peer connections.

   

   I haven’t investigated any deeper than this yet.

5. 
   mzumsande commented at 9:52 pm on May 7, 2024: contributor

   I could not reproduce an OOM, although I did observe resource usage increasing a little before eventually plateauing.

   I see the same kind of behavior with Ubuntu with REST, the memory usage saturates after a few calls. So it looks like the same issue as in #25229 - at least for me.

6. maflcko added the label RPC/REST/ZMQ on May 8, 2024
7. maflcko added the label Resource usage on May 8, 2024
8. 
   maflcko commented at 10:11 am on May 8, 2024: member

   Did the same check with

   0valgrind --tool=massif ./src/bitcoind &
   1while sleep 3; do ./src/bitcoin-cli getblock 00000000000000000002a7c4c1e48d76c5a37902165a270156b7a8d72728a054 2  ; done
   2
   3...
   4
   5massif-visualizer ./massif.out.1234
   

   

9. 
   maflcko commented at 10:11 am on May 8, 2024: member

   Closing for now, as duplicate
10. maflcko closed this on May 8, 2024

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11. ryanofsky referenced this in commit 0503cbea9a on May 13, 2024
12. bitcoin locked this on May 8, 2025

Contributors
achow101 maflcko willcl-ark mzumsande

Labels
RPC/REST/ZMQ Resource usage