Is there something managing user concurrent sessions?

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)

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);
        }
    }
}