Replace catch with try/catch in handle_leader/2#596
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The catch expression captured the full exception term including the stacktrace, which could contain the entire Ra server state in its function arguments. Logging this with ~p caused io_lib_pretty to traverse the massive term, triggering extreme memory allocation and OOM crashes for servers with large machine states (e.g. millions of messages). In this case the node crashed due to OOM because there was a function_clause error in the state machine implementation where the state machine had a huge state. We still need the stack trace to locate where the function_clause originates from.
kjnilsson
approved these changes
Mar 19, 2026
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The catch expression captured the full exception term including
the stacktrace, which could contain the entire Ra server state
in its function arguments. Logging this with ~p caused
io_lib_pretty to traverse the massive term, triggering extreme
memory allocation and OOM crashes for servers with large machine
states (e.g. millions of messages).
In this case the node crashed due to OOM because there was a
function_clause error in the state machine implementation where the
state machine had a huge state.
We still need the stack trace to locate where the function_clause
originates from.
Prior to this commit, the following function_clause caused the node to run out of memory. With this commit, we will get the following log printed: