Spring LDAP failover instead of fallback

Question

In a Spring-boot application we use spring-ldap to query an OpenLDAP server. The connection to the LDAP server is made like this:

    public LdapContextSource contextSource () {
        LdapContextSource contextSource= new LdapContextSource();
        contextSource.setUrl(env.getRequiredProperty("ldap.url"));
        contextSource.setBase(env.getRequiredProperty("ldap.base"));
        contextSource.setUserDn(env.getRequiredProperty("ldap.user"));
        contextSource.setPassword(env.getRequiredProperty("ldap.password"));
        return contextSource;
    }

The ldap.url contains: ldap://ldap1.example.com:389

Yesterday, I installed a second OpenLDAP instance and configured a Multi-Master replication. All is fine and my changes replicate correctly.

I changed the code to connect like this:

    public LdapContextSource contextSource () {
        LdapContextSource contextSource= new LdapContextSource();
        contextSource.setUrls(
                StringUtils.stripAll(
                        StringUtils.split(env.getRequiredProperty("ldap.urls"),',')));
        contextSource.setBase(env.getRequiredProperty("ldap.base"));
        contextSource.setUserDn(env.getRequiredProperty("ldap.user"));
        contextSource.setPassword(env.getRequiredProperty("ldap.password"));
        return contextSource;
    }

The ldap.urls contains: ldap://ldap1.example.com:389,ldap://ldap2.example.com:389

The actual behavior is a fall back mechanism:

1. Both ldap1 and ldap2 are running
2. I force a configuration change
3. The java code does it on ldap1.
4. ldap1 replicates to ldap2 within a few seconds. All is fine.
5. I stop ldap1 and force a configuration change.
6. The java code tries to do it on ldap1, timeout after a few seconds, does it on ldap2.
7. I force a configuration change.
8. The java code tries to do it on ldap1, timeout after a few seconds, does it on ldap2.
9. I start ldap1. ldap2 replicates the pending changes. All is fine.
10. I force a configuration change.
11. The java code does it on ldap1.
12. ldap1 replicates to ldap2 within a few seconds. All is fine.

The behavior I expect would be a fail-over:

1. Both ldap1 and ldap2 are running
2. I force a configuration change
3. The java code does it on ldap1.
4. ldap1 replicates to ldap2 within a few seconds. All is fine.
5. I stop ldap1 and force a configuration change.
6. The java code tries to do it on ldap1, timeout after a few seconds, does it on ldap2.
7. I force a configuration change.
8. The java code tries to do it on ldap2.
9. I start ldap1. ldap2 replicates the pending changes. All is fine.
10. I force a configuration change.
11. The java code does it on ldap1.
12. ldap1 replicates to ldap2 within a few seconds. All is fine.

I mean. I would like that once the ldap1 is detected as problematic, spring goes to ldap2 until ldap2 is problematic.

I tried to reduce timeout but did not succeed. I had a look at the pool notion but wasn't sure this was the right way to address this.

Thank you in advance.