socket failed: EMFILE (Too many open files)

Hi, I am using Retrofit 2.0.0. OkHttp 3.1.2. Some of my users are getting the following exception:

java.net.SocketException: socket failed: EMFILE (Too many open files) at libcore.io.IoBridge.socket(IoBridge.java:619) ~[na:0.0] at java.net.PlainSocketImpl.create(PlainSocketImpl.java:198) ~[na:0.0] at java.net.Socket.checkOpenAndCreate(Socket.java:689) ~[na:0.0] at java.net.Socket.setSoTimeout(Socket.java:543) ~[na:0.0] at com.android.org.conscrypt.OpenSSLSocketImpl.setSoTimeout(OpenSSLSocketImpl.java:1140) ~[na:0.0] at com.android.org.conscrypt.OpenSSLSocketImplWrapper.setSoTimeout(OpenSSLSocketImplWrapper.java:111) ~[na:0.0] at okhttp3.internal.io.RealConnection.connectSocket(RealConnection.java:155) ~[na:0.0] at okhttp3.internal.io.RealConnection.connect(RealConnection.java:111) ~[na:0.0] at okhttp3.internal.http.StreamAllocation.findConnection(StreamAllocation.java:188) ~[na:0.0] at okhttp3.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:127) ~[na:0.0] at okhttp3.internal.http.StreamAllocation.newStream(StreamAllocation.java:97) ~[na:0.0] at okhttp3.internal.http.HttpEngine.connect(HttpEngine.java:289) ~[na:0.0] at okhttp3.internal.http.HttpEngine.sendRequest(HttpEngine.java:241) ~[na:0.0] at okhttp3.RealCall.getResponse(RealCall.java:240) ~[na:0.0] at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:198) ~[na:0.0]

When i look at crashlytics i see a lot of threads which are running:

at com.android.org.conscrypt.NativeCrypto.SSL_read(NativeCrypto.java) at com.android.org.conscrypt.OpenSSLSocketImpl$SSLInputStream.read(OpenSSLSocketImpl.java:811) at okio.Okio$2.read(Okio.java:139) at okio.AsyncTimeout$2.read(AsyncTimeout.java:211) at okio.RealBufferedSource.request(RealBufferedSource.java:71) at okio.RealBufferedSource.require(RealBufferedSource.java:64) at okio.RealBufferedSource.readInt(RealBufferedSource.java:232) at okhttp3.internal.framed.Spdy3$Reader.nextFrame(Spdy3.java:129) at okhttp3.internal.framed.FramedConnection$Reader.execute(FramedConnection.java:600) at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32) at java.lang.Thread.run(Thread.java:818)

I am initiating Okhttp only once in my app this way: `OkHttpClient.Builder clientBuilder = new OkHttpClient.Builder(); clientBuilder.connectTimeout(3 * 1000, TimeUnit.MILLISECONDS); clientBuilder.readTimeout(25 * 1000, TimeUnit.MILLISECONDS);

    File cacheDir = new File(mWeakContext.get().getFilesDir().getAbsolutePath(), "http-cache");
    Cache cache = new Cache(cacheDir, 16 * 1024 * 1024); // 16MB
    clientBuilder.cache(cache);

    // set proxy
    Properties properties = System.getProperties();
    if (properties.containsKey("https.proxyHost")) {

        String proxyHost = properties.getProperty("https.proxyHost");
        int proxyPort = Integer.parseInt(properties.getProperty("https.proxyPort"));

        clientBuilder.proxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress(
                proxyHost,
                proxyPort)
        ));
    }
    clientBuilder.addInterceptor(mHeadersInterceptor);
    clientBuilder.addInterceptor(mSignInterceptor);
    clientBuilder.addInterceptor(mLoggingInterceptor);
    mClient = clientBuilder.build();`

I am pretty clueless here since it doesn’t happen a lot and i cant reproduce it on my device.

[rahulchowdhury]

In case anyone’s still looking for a possible solution, here’s one,

I made the mistake of instantiating OkHttpClient on every API call while injecting dependencies manually in my app, which resulted in too many open sockets and thus this error.

Tip: Make sure you are having a single instance of OkHttpClient and Retrofit in your app and reusing that.

[erlangparasu]

https://github.com/square/okhttp/issues/1943#issuecomment-151024020