Is there something managing user concurrent sessions?

The following utility methods returns you requested informations, so they could be called on login. Please note, that is makes use of internal APIs.

package internals;

import java.util.List;
import java.util.concurrent.Callable;
import java.util.stream.Stream;

import org.apache.commons.lang.StringUtils;

import ch.ivyteam.ivy.security.ISecurityManager;
import ch.ivyteam.ivy.security.ISession;
import ch.ivyteam.ivy.security.internal.SecurityManager;


public class SessionUtils {
    public static boolean isUserLoggedInInOtherSessionAsSystem(String userName) {
        return executeAsSystem(() -> isUserLoggedInInOtherSession(userName));
    }

    public static boolean isUserLoggedInInOtherSession(String userName) {
        return getOtherSessionOfUser(userName).findFirst().isPresent();
    }

    public static void logoutUserFromOtherSessionsAsSystem(String userName) {
        executeAsSystem(() -> logoutUserFromOtherSessions(userName));
    }

    public static Void logoutUserFromOtherSessions(String userName) {
        getOtherSessionOfUser(userName).forEach(session -> session.logoutSessionUser());
        return null;
    }

    public static Stream<ISession> getOtherSessionOfUser(String userName)
    {
        if (StringUtils.isBlank(userName)) {
            return Stream.empty();
        }
        ISecurityManager securityManager = SecurityManager.getSecurityManager();
        ISession currentSession = securityManager.getCurrentSession();
        List<ISession> allSessions = securityManager.getSessions();
        return allSessions.stream()
                .filter(session -> session != currentSession)
                .filter(session -> userName.equals(session.getSessionUserName()));
    }

    private static <R> R executeAsSystem(Callable<R> callable)
    {
        try {
            return SecurityManager.getSecurityManager().executeAsSystem(callable);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

You could implement an ch.ivyteam.ivy.security.ISessionExtension for that. It can be registered on the SecurityManager e.g.

SecurityManager.getSecurityManager().addSessionExtension(ISessionExtension ext)