Hello, I have noticed cases where executing CHECKENGINE displays some

Typically, a Gateway restart should not be an issue, unless a gateway is restarting continuously. However, it is still important to address the cause of the Gateway restart, to ensure that the message can be safely dis-regarded (if the gateway restarted a couple of times.

Also, note that the message will be cleared from the check-engine script, once you do a complete restart of the Appian Engines.

To investigate the cause of your restart further, can you attach:
a) The complete check-engine log
b) The gw_*.log and db_*.log for one of the Appian Engines where you see the message "Gateway has restarted # times"?

The check-engine log will provide the time stamp from when the Gateway restart and I would like to check the gw_*.log for the root cause of the Gateway restart.

The check engine log you refer to is just outputting the output of the checkengine.bat script to a file?

I am attaching the information you requested

engine_logs.zip

As mentioned above an ERROR is a messsage that indicates something went wrong (invalid transaction, couldn't append transaction,etc) that forced the engine to restart to recover from that state. I doesn't mean there's an actual issue at the moment, there was one but the engine was able to successfully recover from that state.

ERROR messsages are cleared after an engine restart.

To investigate the issue you do the following:

1. Review the checkengine output to determine the time when the issue occurred. From your output this happened on:

20 days 23 hrs ago (2015-04-07 17:26:38.048 GMT)

for Process-Design

2. You review the gw_*.log to confirm the restart happened and to see if you can determine the root cause. From your logs I do see the restart in this log but no root cause is explained there

2015-04-07 17:26:39 [PD1] INFO .a.gw "State transition from [STANDALONE] to [DISCONNECTED]"
2015-04-07 17:27:02 [PD1] INFO .a.gw.ssd "Connected to server"
2015-04-07 17:27:02 [PD1] INFO .a.gw "State transition from [DISCONNECTED] to [ACTIVE JOIN]"
2015-04-07 17:27:03 [PD1] INFO .a.gw.swj "No other gateways configured, switching to [STANDALONE]"
2015-04-07 17:27:03 [PD1] INFO .a.gw "State transition from [ACTIVE JOIN] to [STANDALONE]"

3. You then review the corresponding db_*.log to find out the root cause using the same time stamp that checkengine provided. From your log the root cause is:

2015-04-07 17:26:37 [PD1] {pd606.kdb 16576} (Default) ERROR .a.s.loader "Failed to append transaction to DB ("pd606.kdb: The handle is invalid."), will delay one second and retry once."
2015-04-07 17:26:38 [PD1] {pd606.kdb 16576} (Default) ERROR .a.s.loader "Retry failed: "pd606.kdb: The handle is invalid.""

4. A message of type "The handle is invalid" causes a restart in the engine because it cannot write the transaction to disk because the *.kdb file was locked by an external source.

5. To prevent the issue make sure your back-up tool, antivirus or any other scanning tool doesn't lock files that Appian needs. Nothing in the <APPIAN_HOME> directory can be locked at any time otherwise this error will occur.

Eduardo thank you very much for your explanation in this issue.