SLF4J bridge for LOG4J2 causing problems with apache HttpClient

[AndreG-P]

So I changed, all loggings to log4j2. Essentially by adding 2 dependencies:

        <!-- Logging via log4j2 -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.10.0</version>
        </dependency>

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.10.0</version>
        </dependency>

Since some other dependencies (for example flink) using log4j (not log4j2) we need to import the bridge.

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-1.2-api</artifactId>
            <version>2.10.0</version>
        </dependency>

Everything works fine but, why ever, it looks like flink uses slf4j for logging, just at the startup. Fine, let's add a bridge for slf4j also:

        <dependency> <!-- Redirect all slf4j logging to log4j2 -->
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j-impl</artifactId>
            <version>2.10.0</version>
        </dependency>

Now the error in the beginning (cannot ).
BUT! Suddenly, the caching HttpClient gets an error:

org.apache.http.impl.execchain.RequestAbortedException: Request aborted
	at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:194)
	at org.apache.http.impl.client.cache.CachingExec.callBackend(CachingExec.java:592)
	at org.apache.http.impl.client.cache.CachingExec.execute(CachingExec.java:269)
	at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:185)
	at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
	at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:111)
	at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
	at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
	at com.formulasearchengine.mathosphere.mlp.text.TexInfo.makeRequest(TexInfo.java:81)
	at com.formulasearchengine.mathosphere.mlp.text.TexInfo.getIdentifiers(TexInfo.java:108)
        ...

Removing the logging bridge for slf4j solves this error, but produces a warning in the beginning.