Fix Thread-Safety in the SyslogToMapTransformer [INT-3715]

[spring-operator]

Alvaro Vega opened INT-3715 and commented

Syslog-udp module is creating wrong timestamp fields (even another numeric fields are bad transformed)
Checking the output from Java Mission Control, we have seen that Spring Integration component udp-inbound-channel-adapter is used, and also DatagramPacketMessageMapper in method toMessage, and in here might be the problem in a concurrent environment, with different threads accessing some share variable.
Attatch a file, with the syslog entry sent in a loop, and different output obtained for the same entry.
We used a simple stream syslog-udp | file in a Spring XD single-node, and also failed in a distributed way.

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Affects: 4.1.3

Attachments:

• TestSyslog-udp-4-Pivotal.txt (8.46 kB)

Referenced from: pull request #1443

Backported to: 4.0.8, 3.0.8

[spring-operator]

Karol Dowbecki commented

org.springframework.integration.transformer.SyslogToMapTransformer#transform(String) is being invoked by multiple ip:udp-inbound-channel-adapter threads. This method is accessing SyslogToMapTransformer#dateFormat field implemented with SimpleDateFormat without any synchronization.

Although one can create new local SimpleDateFormat object or use ThreadLocal perhaps spring-integration-syslog should use a thread-safe formatter e.g. FastDateFormat from commons-lang?

[spring-operator]

Gary Russell commented

Hi Karol Dowbecki

We can't add a new dependency to 4.1.x, but we can look at doing so for 4.2.x

In the meantime, we can use a pool.

[spring-operator]

Karol Dowbecki commented

I've checked commons-lang 3.4 and 3.5-SNAPSHOT and unfortunately FastDateFormat is not a drop-in replacement for SimpleDateFormat:

1. MMM pattern is case-sensitive e.g. "may" parses but "May" doesn't. Both values work with SimpleDateFormat.
2. Leading zeros in dd are required e.g. "08" parses but " 8" doesn't. Both values work with SimpleDateFormat.

Please ignore my previous comment about commons-lang.

[spring-operator]

Gary Russell commented

Thanks; I guess we'll stick with what I did in the PR.