Hello
I am seeing the error below in my cassandra server logs. I am running cassandra
3.11.13. I understand the version is old. I know a lot of people run old
cassandra versions. Has anyone seen this error in the past.
What concerns me is that, after this error it appears the server appeared to
silently restart. I see the startup time messages
INFO [main] 2025-10-21 19:06:55,713 Gossiper.java:1900 - No gossip backlog;
proceeding
INFO [main] 2025-10-21 19:06:56,622 NativeTransportService.java:68 - Netty
using native Epoll event loop
Is this how it is supposed to work?
INFO [Service Thread] 2025-10-21 18:56:14,400 GCInspector.java:285 - G1 Young
Generation GC in 289ms. G1 Eden Space: 1451229184 -> 0; G1 Old Gen: 7839154160
-> 7436500976;
ERROR [PerDiskMemtableFlushWriter_0:1] 2025-10-21 18:56:55,885
CassandraDaemon.java:244 - Exception in thread
Thread[PerDiskMemtableFlushWriter_0:1,5,main]
java.lang.ClassCastException: <unknown> cannot be cast to
org.apache.cassandra.db.rows.ColumnData
at
org.apache.cassandra.utils.btree.BTree$FiltrationTracker.apply(BTree.java:681)
at
org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:724)
at
org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:699)
at
org.apache.cassandra.db.rows.BTreeRow.transformAndFilter(BTreeRow.java:430)
at org.apache.cassandra.db.rows.BTreeRow.filter(BTreeRow.java:298)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.consumeNextRow(RowAndDeletionMergeIterator.java:178)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNextInternal(RowAndDeletionMergeIterator.java:97)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNext(RowAndDeletionMergeIterator.java:144)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNext(RowAndDeletionMergeIterator.java:35)
at
org.apache.cassandra.utils.AbstractIterator.hasNext(AbstractIterator.java:47)
at org.apache.cassandra.db.transform.BaseRows.hasNext(BaseRows.java:133)
at
org.apache.cassandra.db.ColumnIndex.buildRowIndex(ColumnIndex.java:110)
at
org.apache.cassandra.io.sstable.format.big.BigTableWriter.append(BigTableWriter.java:173)
at
org.apache.cassandra.io.sstable.SimpleSSTableMultiWriter.append(SimpleSSTableMultiWriter.java:48)
at
org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:482)
at
org.apache.cassandra.db.Memtable$FlushRunnable.call(Memtable.java:517)
at
org.apache.cassandra.db.Memtable$FlushRunnable.call(Memtable.java:404)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at
org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:84)
at java.lang.Thread.run(Thread.java:750)
ERROR [MemtablePostFlush:1] 2025-10-21 18:56:55,951 CassandraDaemon.java:244 -
Exception in thread Thread[MemtablePostFlush:1,5,main]
java.lang.RuntimeException: java.util.concurrent.ExecutionException:
java.lang.ClassCastException: <unknown> cannot be cast to
org.apache.cassandra.db.rows.ColumnData
at org.apache.cassandra.utils.Throwables.maybeFail(Throwables.java:62)
at
org.apache.cassandra.utils.FBUtilities.waitOnFutures(FBUtilities.java:430)
at
org.apache.cassandra.utils.FBUtilities.waitOnFutures(FBUtilities.java:393)
at
org.apache.cassandra.db.ColumnFamilyStore$Flush.flushMemtable(ColumnFamilyStore.java:1202)
at
org.apache.cassandra.db.ColumnFamilyStore$Flush.run(ColumnFamilyStore.java:1143)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at
org.apache.cassandra.concurrent.NamedThreadFactory.lambda$threadLocalDeallocator$0(NamedThreadFactory.java:84)
at java.lang.Thread.run(Thread.java:750)
Caused by: java.util.concurrent.ExecutionException:
java.lang.ClassCastException: <unknown> cannot be cast to
org.apache.cassandra.db.rows.ColumnData
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:192)
at
org.apache.cassandra.utils.FBUtilities.waitOnFutures(FBUtilities.java:417)
... 7 common frames omitted
Caused by: java.lang.ClassCastException: <unknown> cannot be cast to
org.apache.cassandra.db.rows.ColumnData
at
org.apache.cassandra.utils.btree.BTree$FiltrationTracker.apply(BTree.java:681)
at
org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:724)
at
org.apache.cassandra.utils.btree.BTree.transformAndFilter(BTree.java:699)
at
org.apache.cassandra.db.rows.BTreeRow.transformAndFilter(BTreeRow.java:430)
at org.apache.cassandra.db.rows.BTreeRow.filter(BTreeRow.java:298)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.consumeNextRow(RowAndDeletionMergeIterator.java:178)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNextInternal(RowAndDeletionMergeIterator.java:97)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNext(RowAndDeletionMergeIterator.java:144)
at
org.apache.cassandra.db.rows.RowAndDeletionMergeIterator.computeNext(RowAndDeletionMergeIterator.java:35)
at
org.apache.cassandra.utils.AbstractIterator.hasNext(AbstractIterator.java:47)
at org.apache.cassandra.db.transform.BaseRows.hasNext(BaseRows.java:133)
at
org.apache.cassandra.db.ColumnIndex.buildRowIndex(ColumnIndex.java:110)
at
org.apache.cassandra.io.sstable.format.big.BigTableWriter.append(BigTableWriter.java:173)
at
org.apache.cassandra.io.sstable.SimpleSSTableMultiWriter.append(SimpleSSTableMultiWriter.java:48)
at
org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:482)
at
org.apache.cassandra.db.Memtable$FlushRunnable.call(Memtable.java:517)
at
org.apache.cassandra.db.Memtable$FlushRunnable.call(Memtable.java:404)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
... 4 common frames omitted
I checked dmesg output
[Tue Oct 21 19:00:18 2025] INFO: task java:24431 blocked for more than 122
seconds.
[Tue Oct 21 19:00:18 2025] Not tainted 6.8.0-1031-aws #33~22.04.1-Ubuntu
[Tue Oct 21 19:00:18 2025] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[Tue Oct 21 19:00:18 2025] task:java state:D stack:0 pid:24431
tgid:24431 ppid:1 flags:0x00004002
[Tue Oct 21 19:00:18 2025] Call Trace:
[Tue Oct 21 19:00:18 2025] <TASK>
[Tue Oct 21 19:00:18 2025] __schedule+0x27c/0x680
[Tue Oct 21 19:00:18 2025] schedule+0x2c/0xf0
[Tue Oct 21 19:00:18 2025] do_exit+0x117/0x510
[Tue Oct 21 19:00:18 2025] do_group_exit+0x35/0x90
[Tue Oct 21 19:00:18 2025] get_signal+0x963/0x970
[Tue Oct 21 19:00:18 2025] arch_do_signal_or_restart+0x39/0x120
[Tue Oct 21 19:00:18 2025] syscall_exit_to_user_mode+0x206/0x260
[Tue Oct 21 19:00:18 2025] do_syscall_64+0x8d/0x170
[Tue Oct 21 19:00:18 2025] ? __update_load_avg_cfs_rq+0x212/0x2a0
[Tue Oct 21 19:00:18 2025] ? place_entity+0xf0/0x100
[Tue Oct 21 19:00:18 2025] ? __enqueue_entity+0x109/0x150
[Tue Oct 21 19:00:18 2025] ? enqueue_entity+0xfc/0x570
[Tue Oct 21 19:00:18 2025] ? enqueue_task_fair+0x1b7/0x360
[Tue Oct 21 19:00:18 2025] ? x2apic_send_IPI+0x5d/0x90
[Tue Oct 21 19:00:18 2025] ? native_smp_send_reschedule+0x1f/0x50
[Tue Oct 21 19:00:18 2025] ? resched_curr+0x5e/0x140
[Tue Oct 21 19:00:18 2025] ? _raw_spin_unlock_irqrestore+0x11/0x40
[Tue Oct 21 19:00:18 2025] ? wake_up_new_task+0x22b/0x300
[Tue Oct 21 19:00:18 2025] ? __raw_spin_unlock_irq+0x9/0x20
[Tue Oct 21 19:00:18 2025] ? sigprocmask+0xb4/0xe0
[Tue Oct 21 19:00:18 2025] ? __x64_sys_rt_sigprocmask+0x7f/0xe0
[Tue Oct 21 19:00:18 2025] ? syscall_exit_to_user_mode+0x86/0x260
[Tue Oct 21 19:00:18 2025] ? do_syscall_64+0x8d/0x170
[Tue Oct 21 19:00:18 2025] ? __do_sys_clone3+0xf6/0x130
[Tue Oct 21 19:00:18 2025] ? syscall_exit_to_user_mode+0x86/0x260
[Tue Oct 21 19:00:18 2025] ? do_syscall_64+0x8d/0x170
[Tue Oct 21 19:00:18 2025] ? irqentry_exit_to_user_mode+0x7b/0x260
[Tue Oct 21 19:00:18 2025] ? irqentry_exit+0x21/0x40
[Tue Oct 21 19:00:18 2025] ? exc_page_fault+0x94/0x190
[Tue Oct 21 19:00:18 2025] entry_SYSCALL_64_after_hwframe+0x78/0x80
[Tue Oct 21 19:00:18 2025] RIP: 0033:0x7405dd291117
[Tue Oct 21 19:00:18 2025] RSP: 002b:00007ffea0bf25a0 EFLAGS: 00000246
ORIG_RAX: 00000000000000ca
[Tue Oct 21 19:00:18 2025] RAX: fffffffffffffe00 RBX: 00007405dd4b4640 RCX:
00007405dd291117
[Tue Oct 21 19:00:18 2025] RDX: 0000000000005f70 RSI: 0000000000000109 RDI:
00007405dd4b4910
[Tue Oct 21 19:00:18 2025] RBP: 00007ffea0bf2668 R08: 0000000000000000 R09:
00000000ffffffff
[Tue Oct 21 19:00:18 2025] R10: 0000000000000000 R11: 0000000000000246 R12:
0000000000000000
[Tue Oct 21 19:00:18 2025] R13: 0000000000005f70 R14: 0000000000000000 R15:
0000000000000000
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