java.lang.OutOfMemoryError: Direct buffer memory Apache Ignite - jvm

Question

Recently we moved to 64 bit JVM with ignite 2.10.0, our cache configuration looks like following (was working alright with 2.9.0),
_cfg = new IgniteConfiguration()
{
IgniteInstanceName = MKT_TICK_DATA_CACHE,
DiscoverySpi = new TcpDiscoverySpi
{
LocalPort = 48500,
LocalPortRange = 60,
IpFinder = new TcpDiscoveryStaticIpFinder
{
Endpoints = new[] { "127.0.0.1:48500..48560" }
}
},
CommunicationSpi = new TcpCommunicationSpi
{
LocalPort = 48100
},
DataStorageConfiguration = new DataStorageConfiguration
{
DefaultDataRegionConfiguration = new DataRegionConfiguration
{
Name = MKT_TICK_DATA_CACHE,
InitialSize = 500L * 1024 * 1024,
MaxSize = 4L * 1024 * 1024 * 1024,
PersistenceEnabled = false,
PageEvictionMode = Apache.Ignite.Core.Configuration.DataPageEvictionMode.Random2Lru
},
SystemRegionInitialSize = 100 * 1024 * 1024
},
ClientConnectorConfiguration = new ClientConnectorConfiguration
{
// Set a port range from 10000 to 10005
Port = 10800,
PortRange = 60,
HandshakeTimeout = TimeSpan.FromSeconds(30),
IdleTimeout = Timeout.InfiniteTimeSpan,
MaxOpenCursorsPerConnection = 10000,
SocketReceiveBufferSize = 100 * 1024 * 1024,
SocketSendBufferSize = 100 * 1024 * 1024,
TcpNoDelay = true,
ThinClientEnabled = true,
ThreadPoolSize = 256
},
JvmOptions = new System.Collections.Generic.List<String>() { "-Xms1g", "-Xmx20g", "-XX:+AlwaysPreTouch", "-XX:+UseG1GC", "-XX:+ScavengeBeforeFullGC", "-XX:+DisableExplicitGC", "-Djava.net.preferIPv4Stack=true", "-XX:MaxDirectMemorySize=30G" }
//JvmOptions = new System.Collections.Generic.List<String>() { "-XX:+AlwaysPreTouch", "-XX:+UseG1GC", "-XX:+ScavengeBeforeFullGC", "-XX:+DisableExplicitGC", "-Djava.net.preferIPv4Stack=true" }
//JvmOptions = new[] { "-Xmx10g" },//, "-XX:+AlwaysPreTouch", "-XX:+UseG1GC", "-XX:+ScavengeBeforeFullGC", "-XX:+DisableExplicitGC" }
};
_cfg.ServiceThreadPoolSize = 256;
_cfg.SystemThreadPoolSize = 128;
_cfg.StripedThreadPoolSize = 128;
_cfg.WorkDirectory = _dir;
var cacheConfig = new CacheConfiguration
{
Name = MKT_TICK_DATA_CACHE,
CacheMode = CacheMode.Partitioned,
Backups = 0,
AtomicityMode = CacheAtomicityMode.Atomic,
LoadPreviousValue = false,
OnheapCacheEnabled = true,
WriteBehindEnabled = false,
WriteSynchronizationMode = CacheWriteSynchronizationMode.FullAsync,
MaxConcurrentAsyncOperations = 300000
};
_cfg.CacheConfiguration = new CacheConfiguration[] { cacheConfig };
Ignition.ClientMode = false;
var ignite = Ignition.Start(_cfg);
_cache = ignite.GetOrCreateCache<Int32, MarketTickS>(MKT_TICK_DATA_CACHE);
_oCache = ignite.GetOrCreateCache<Int64, byte[]>(ORION_L_CACHE);
_oSecCache = ignite.GetOrCreateCache<Int64, CacheSecurity>(ORION_SEC_CACHE);
our cache crashes about 15 mins of running. Role of this cache is to store tick data from market, which is coming in rate # 60K ticks per second.
[14:03:01,528][SEVERE][grid-nio-worker-client-listener-13-#197%QTICKDATA%][] JVM will be halted immediately due to the failure: [failureCtx=FailureContext [type=CRITICAL_ERROR, err=java.lang.OutOfMemoryError: Direct buffer memory]]
Could you help please?
*********** Update ******************************
Updates, after a JDK reinstall on the server. Crash did not happen after 60 minutes of continuous operation. However, still curious Ignite 2.9 takes 3.X GB total ram, but ignite 2.10 takes 32.x GB total ram with same cache configurations (Same set of C# binaries, except ignite with 32.x GB memory is 2.10, and with 3.x GB memory is 2.9). Snap shots attached below,
with 2.9,

Answer 1

Try to remove -XX:+DisableExplicitGC switch, it is known to interfere with direct buffer memory allocation, and therefore no longer recommended.
Not sure why it takes more RAM than before, need more details.