Estou usando o cliente http Apache 4.3.2 para enviar solicitações de obtenção. O que eu fiz é:

private final RequestConfig requestConfig = RequestConfig.custom()
        .setConnectTimeout(1000)
        .setConnectionRequestTimeout(1000)
        .setSocketTimeout(1000)
        .build();
private final HttpClient client = HttpClientBuilder.create()
        .disableAuthCaching()
        .disableAutomaticRetries()
        .disableConnectionState()
        .disableContentCompression()
        .disableCookieManagement()
        .disableRedirectHandling()
        .setDefaultRequestConfig(requestConfig)
        .build(); 

E ao enviar solicitação:

HttpGet request = null;

try {
    request = new HttpGet(url);
    if (client.execute(request).getStatusLine().getStatusCode() == 200) {
        /* do some work here */
    }
} catch (Exception e) {
    Logger.error(e);
} finally {
    if (request != null) {
        request.releaseConnection();
    }
}

Mas alguns dos meus pedidos ainda levam muito tempo para atingir o tempo limite. Este é o rastreamento de pilha da exceção:

java.net.SocketTimeoutException: Read timed out
    at java.net.SocketInputStream.socketRead0(Native Method)
    at java.net.SocketInputStream.read(SocketInputStream.java:152)
    at java.net.SocketInputStream.read(SocketInputStream.java:122)
    at org.apache.http.impl.io.SessionInputBufferImpl.streamRead(SessionInputBufferImpl.java:136)
    at org.apache.http.impl.io.SessionInputBufferImpl.fillBuffer(SessionInputBufferImpl.java:152)
    at org.apache.http.impl.io.SessionInputBufferImpl.readLine(SessionInputBufferImpl.java:270)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:140)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:57)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:260)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:161)
    at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.http.impl.conn.CPoolProxy.invoke(CPoolProxy.java:138)
    at com.sun.proxy.$Proxy0.receiveResponseHeader(Unknown Source)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:271)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:123)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:254)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:195)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57)

Existe algum outro valor de tempo limite que devo definir? O que estou fazendo errado?