长事务导致数据库挂了，求解答

[weiyongzhi2005]

数据库完全卡死了，一查看发现有个长事务，然后把online.log日志调出来看了下，发现下面这个时间点，逻辑日志缓冲区好像出问题了，然后服务器连接数一下子疯涨了，后面就一直到3600多不变化了
求哪位大神帮我解释下这日志是啥意思，小弟没整明白

15:35:52 Maximum server connections 1459
15:35:52 Checkpoint Statistics - Avg. Txn Block Time 1.001, # Txns blocked 7, Plog used 31595, Llog used 17368

15:52:46 Checkpoint Completed: duration was 952 seconds.
15:52:46 Mon Oct 10 - loguniq 62844, logpos 0x85bc398, timestamp: 0x9e7a9e2e Interval: 338054

15:52:46 Maximum server connections 1708
15:52:46 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 1, Plog used 14722, Llog used 10781

15:54:13 Checkpoint log record may not fit into the logical log buffer.
Recommended minimum value for LOGBUFF is 68.
16:30:39 Checkpoint Completed: duration was 2241 seconds.
16:30:39 Mon Oct 10 - loguniq 62844, logpos 0xa6c3048, timestamp: 0x9e9ace54 Interval: 338055

16:30:39 Maximum server connections 2471
16:30:39 Checkpoint Statistics - Avg. Txn Block Time 1.001, # Txns blocked 1, Plog used 14874, Llog used 28414

17:03:48 sid 64937197 username informix@tnmsdb1 pid 8651194 terminated.
17:03:53 sid 64937197 username informix@tnmsdb1 pid 8651194 terminated.
17:23:26 Checkpoint Completed: duration was 3134 seconds.
17:23:26 Mon Oct 10 - loguniq 62844, logpos 0xf5dc130, timestamp: 0x9ec60b5e Interval: 338056

17:23:26 Maximum server connections 3141
17:23:26 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 1, Plog used 33966, Llog used 48050

18:29:50 Checkpoint Completed: duration was 3952 seconds.
18:29:50 Mon Oct 10 - loguniq 62844, logpos 0x163a4048, timestamp: 0x9effde76 Interval: 338057

18:29:50 Maximum server connections 3610
18:29:50 Checkpoint Statistics - Avg. Txn Block Time 1.001, # Txns blocked 2, Plog used 45832, Llog used 63376

18:59:09 Checkpoint Completed: duration was 1757 seconds.
18:59:09 Mon Oct 10 - loguniq 62844, logpos 0x1ed6f018, timestamp: 0x9f02f569 Interval: 338058