我们一起学ignite之GridNioServer及build

一起学 ignite 源码分析

转载请注明本文作者：aloxc，邮箱leerohwa#gmail.com[#更换为@]

如题，ignite还支持memcache协议，具体就是ignite启动的时候启动了一个绑定到11211--11310这100个端口中的一个的nio服务。

这100个端口是这样选择的，初始是从11211端口起一个nio服务，如果起的这个nio服务没启动成功起来就往之前的端口加1后再次起nio服务，至到成功的起了一个nio服务。
相关代码（org.apache.ignite.internal.processors.rest.protocols.tcp.GridTcpRestProtocol中）如下

public void start(final GridRestProtocolHandler hnd) throws IgniteCheckedException {
        assert hnd != null;
        ConnectorConfiguration cfg = ctx.config().getConnectorConfiguration();
        assert cfg != null;
        lsnr = new GridTcpRestNioListener(log, this, hnd, ctx);
        GridNioParser parser = new GridTcpRestParser(false);
        try {
            host = resolveRestTcpHost(ctx.config());
            SSLContext sslCtx = null;
            if (cfg.isSslEnabled()) {
                Factory<SSLContext> igniteFactory = ctx.config().getSslContextFactory();
                Factory<SSLContext> factory = cfg.getSslFactory();
                // This factory deprecated and will be removed.
                GridSslContextFactory depFactory = cfg.getSslContextFactory();
                if (factory == null && depFactory == null && igniteFactory == null)
                    // Thrown SSL exception instead of IgniteCheckedException for writing correct warning message into log.
                    throw new SSLException("SSL is enabled, but SSL context factory is not specified.");
                if (factory != null)
                    sslCtx = factory.create();
                else if (depFactory != null)
                    sslCtx = depFactory.createSslContext();
                else
                    sslCtx = igniteFactory.create();
            }
            int startPort = cfg.getPort();
            int portRange = cfg.getPortRange();
            int lastPort = portRange == 0 ? startPort : startPort + portRange - 1;
            for (int port0 = startPort; port0 <= lastPort; port0++) {
                if (startTcpServer(host, port0, lsnr, parser, sslCtx, cfg)) {
                    port = port0;
                    if (log.isInfoEnabled())
                        log.info(startInfo());
                    return;
                }
            }
            IgniteUtils.warn(log, "Failed to start TCP binary REST server (possibly all ports in range are in use) " +
                "[firstPort=" + cfg.getPort() + ", lastPort=" + lastPort + ", host=" + host + ']');
        }
        catch (SSLException e) {
            IgniteUtils.warn(log, "Failed to start " + name() + " protocol on port " + port + ": " + e.getMessage(),
                "Failed to start " + name() + " protocol on port " + port + ". Check if SSL context factory is " +
                    "properly configured.");
        }
        catch (IOException e) {
            IgniteUtils.warn(log, "Failed to start " + name() + " protocol on port " + port + ": " + e.getMessage(),
                "Failed to start " + name() + " protocol on port " + port + ". " +
                    "Check restTcpHost configuration property.");
        }
    }

如果说我们线上服务器，不希望ignite启动后还兼容memcache命令，可以把这个方法中行lsnr = new GridTcpRestNioListener(log, this, hnd, ctx);后面的代码注释掉。其实本人认为ignite这么做兼容别的命令有点画蛇添足，虽然有很多公司在使用memcache，并且也愿意使用ignite的情况下也不会简单的更换到ignite并且还用memcache命令连接ignite，虽然直接替换下memcache地址，接着使用memcache命令连接ignite这样成本较小。我个人不希望ignite这么做，