diff --git a/logstash-core/src/main/java/org/logstash/common/BufferedTokenizerExt.java b/logstash-core/src/main/java/org/logstash/common/BufferedTokenizerExt.java
index be1c64d2356..e2c476520c1 100644
--- a/logstash-core/src/main/java/org/logstash/common/BufferedTokenizerExt.java
+++ b/logstash-core/src/main/java/org/logstash/common/BufferedTokenizerExt.java
@@ -23,14 +23,18 @@
 import org.jruby.Ruby;
 import org.jruby.RubyArray;
 import org.jruby.RubyClass;
+import org.jruby.RubyEncoding;
 import org.jruby.RubyObject;
 import org.jruby.RubyString;
 import org.jruby.anno.JRubyClass;
 import org.jruby.anno.JRubyMethod;
 import org.jruby.runtime.ThreadContext;
 import org.jruby.runtime.builtin.IRubyObject;
+import org.jruby.util.ByteList;
 import org.logstash.RubyUtil;
 
+import java.nio.charset.Charset;
+
 @JRubyClass(name = "BufferedTokenizer")
 public class BufferedTokenizerExt extends RubyObject {
 
@@ -40,10 +44,13 @@ public class BufferedTokenizerExt extends RubyObject {
                                                                 freeze(RubyUtil.RUBY.getCurrentContext());
 
     private @SuppressWarnings("rawtypes") RubyArray input = RubyUtil.RUBY.newArray();
+    private StringBuilder headToken = new StringBuilder();
     private RubyString delimiter = NEW_LINE;
     private int sizeLimit;
     private boolean hasSizeLimit;
     private int inputSize;
+    private boolean bufferFullErrorNotified = false;
+    private String encodingName;
 
     public BufferedTokenizerExt(final Ruby runtime, final RubyClass metaClass) {
         super(runtime, metaClass);
@@ -80,23 +87,76 @@ public IRubyObject init(final ThreadContext context, IRubyObject[] args) {
     @JRubyMethod
     @SuppressWarnings("rawtypes")
     public RubyArray extract(final ThreadContext context, IRubyObject data) {
+        RubyEncoding encoding = (RubyEncoding) data.convertToString().encoding(context);
+        encodingName = encoding.getEncoding().getCharsetName();
         final RubyArray entities = data.convertToString().split(delimiter, -1);
+        if (!bufferFullErrorNotified) {
+            input.clear();
+            input.concat(entities);
+        } else {
+            // after a full buffer signal
+            if (input.isEmpty()) {
+                // after a buffer full error, the remaining part of the line, till next delimiter,
+                // has to be consumed, unless the input buffer doesn't still contain fragments of
+                // subsequent tokens.
+                entities.shift(context);
+                input.concat(entities);
+            } else {
+                // merge last of the input with first of incoming data segment
+                if (!entities.isEmpty()) {
+                    RubyString last = ((RubyString) input.pop(context));
+                    RubyString nextFirst = ((RubyString) entities.shift(context));
+                    entities.unshift(last.concat(nextFirst));
+                    input.concat(entities);
+                }
+            }
+        }
+
         if (hasSizeLimit) {
-            final int entitiesSize = ((RubyString) entities.first()).size();
+            if (bufferFullErrorNotified) {
+                bufferFullErrorNotified = false;
+                if (input.isEmpty()) {
+                    return RubyUtil.RUBY.newArray();
+                }
+            }
+            final int entitiesSize = ((RubyString) input.first()).size();
             if (inputSize + entitiesSize > sizeLimit) {
-                throw new IllegalStateException("input buffer full");
+                bufferFullErrorNotified = true;
+                headToken = new StringBuilder();
+                String errorMessage = String.format("input buffer full, consumed token which exceeded the sizeLimit %d; inputSize: %d, entitiesSize %d", sizeLimit, inputSize, entitiesSize);
+                inputSize = 0;
+                input.shift(context); // consume the token fragment that generates the buffer full
+                throw new IllegalStateException(errorMessage);
             }
             this.inputSize = inputSize + entitiesSize;
         }
-        input.append(entities.shift(context));
-        if (entities.isEmpty()) {
+
+        if (input.getLength() < 2) {
+            // this is a specialization case which avoid adding and removing from input accumulator
+            // when it contains just one element
+            headToken.append(input.shift(context)); // remove head
             return RubyUtil.RUBY.newArray();
         }
-        entities.unshift(input.join(context));
-        input.clear();
-        input.append(entities.pop(context));
-        inputSize = ((RubyString) input.first()).size();
-        return entities;
+
+        if (headToken.length() > 0) {
+            // if there is a pending token part, merge it with the first token segment present
+            // in the accumulator, and clean the pending token part.
+            headToken.append(input.shift(context)); // append buffer to first element and
+            // create new RubyString with the data specified encoding
+            RubyString encodedHeadToken = toEncodedRubyString(context, headToken.toString());
+            input.unshift(encodedHeadToken); // reinsert it into the array
+            headToken = new StringBuilder();
+        }
+        headToken.append(input.pop(context)); // put the leftovers in headToken for later
+        inputSize = headToken.length();
+        return input;
+    }
+
+    private RubyString toEncodedRubyString(ThreadContext context, String input) {
+        // Depends on the encodingName being set by the extract method, could potentially raise if not set.
+        RubyString result = RubyUtil.RUBY.newString(new ByteList(input.getBytes(Charset.forName(encodingName))));
+        result.force_encoding(context, RubyUtil.RUBY.newString(encodingName));
+        return result;
     }
 
     /**
@@ -108,15 +168,30 @@ public RubyArray extract(final ThreadContext context, IRubyObject data) {
      */
     @JRubyMethod
     public IRubyObject flush(final ThreadContext context) {
-        final IRubyObject buffer = input.join(context);
-        input.clear();
+        final IRubyObject buffer = RubyUtil.toRubyObject(headToken.toString());
+        headToken = new StringBuilder();
         inputSize = 0;
-        return buffer;
+
+        // create new RubyString with the last data specified encoding, if exists
+        RubyString encodedHeadToken;
+        if (encodingName != null) {
+            encodedHeadToken = toEncodedRubyString(context, buffer.toString());
+        } else {
+            // When used with TCP input it could be that on socket connection the flush method
+            // is invoked while no invocation of extract, leaving the encoding name unassigned.
+            // In such case also the headToken must be empty
+            if (!buffer.toString().isEmpty()) {
+                throw new IllegalStateException("invoked flush with unassigned encoding but not empty head token, this shouldn't happen");
+            }
+            encodedHeadToken = (RubyString) buffer;
+        }
+
+        return encodedHeadToken;
     }
 
     @JRubyMethod(name = "empty?")
     public IRubyObject isEmpty(final ThreadContext context) {
-        return RubyUtil.RUBY.newBoolean(input.isEmpty() && (inputSize == 0));
+        return RubyUtil.RUBY.newBoolean(headToken.toString().isEmpty() && (inputSize == 0));
     }
 
 }
diff --git a/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtTest.java b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtTest.java
new file mode 100644
index 00000000000..524abb36ed5
--- /dev/null
+++ b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtTest.java
@@ -0,0 +1,161 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.logstash.common;
+
+import org.jruby.RubyArray;
+import org.jruby.RubyEncoding;
+import org.jruby.RubyString;
+import org.jruby.runtime.ThreadContext;
+import org.jruby.runtime.builtin.IRubyObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.logstash.RubyTestBase;
+import org.logstash.RubyUtil;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.logstash.RubyUtil.RUBY;
+
+@SuppressWarnings("unchecked")
+public final class BufferedTokenizerExtTest extends RubyTestBase {
+
+    private BufferedTokenizerExt sut;
+    private ThreadContext context;
+
+    @Before
+    public void setUp() {
+        sut = new BufferedTokenizerExt(RubyUtil.RUBY, RubyUtil.BUFFERED_TOKENIZER);
+        context = RUBY.getCurrentContext();
+        IRubyObject[] args = {};
+        sut.init(context, args);
+    }
+
+    @Test
+    public void shouldTokenizeASingleToken() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo\n"));
+
+        assertEquals(List.of("foo"), tokens);
+    }
+
+    @Test
+    public void shouldMergeMultipleToken() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo"));
+        assertTrue(tokens.isEmpty());
+
+        tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("bar\n"));
+        assertEquals(List.of("foobar"), tokens);
+    }
+
+    @Test
+    public void shouldTokenizeMultipleToken() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo\nbar\n"));
+
+        assertEquals(List.of("foo", "bar"), tokens);
+    }
+
+    @Test
+    public void shouldIgnoreEmptyPayload() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString(""));
+        assertTrue(tokens.isEmpty());
+
+        tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo\nbar"));
+        assertEquals(List.of("foo"), tokens);
+    }
+
+    @Test
+    public void shouldTokenizeEmptyPayloadWithNewline() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("\n"));
+        assertEquals(List.of(""), tokens);
+
+        tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("\n\n\n"));
+        assertEquals(List.of("", "", ""), tokens);
+    }
+
+    @Test
+    public void shouldNotChangeEncodingOfTokensAfterPartitioning() {
+        RubyString rubyString = RubyString.newString(RUBY, new byte[]{(byte) 0xA3, 0x0A, 0x41}); // £ character, newline, A
+        IRubyObject rubyInput = rubyString.force_encoding(context, RUBY.newString("ISO8859-1"));
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>)sut.extract(context, rubyInput);
+
+        // read the first token, the £ string
+        IRubyObject firstToken = tokens.shift(context);
+        assertEquals("£", firstToken.toString());
+
+        // verify encoding "ISO8859-1" is preserved in the Java to Ruby String conversion
+        RubyEncoding encoding = (RubyEncoding) firstToken.callMethod(context, "encoding");
+        assertEquals("ISO-8859-1", encoding.toString());
+    }
+
+    @Test
+    public void shouldNotChangeEncodingOfTokensAfterPartitioningInCaseMultipleExtractionInInvoked() {
+        RubyString rubyString = RubyString.newString(RUBY, new byte[]{(byte) 0xA3}); // £ character
+        IRubyObject rubyInput = rubyString.force_encoding(context, RUBY.newString("ISO8859-1"));
+        sut.extract(context, rubyInput);
+        IRubyObject capitalAInLatin1 = RubyString.newString(RUBY, new byte[]{(byte) 0x41})
+                .force_encoding(context, RUBY.newString("ISO8859-1"));
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>)sut.extract(context, capitalAInLatin1);
+        assertTrue(tokens.isEmpty());
+
+        tokens = (RubyArray<RubyString>)sut.extract(context, RubyString.newString(RUBY, new byte[]{(byte) 0x0A}));
+
+        // read the first token, the £ string
+        IRubyObject firstToken = tokens.shift(context);
+        assertEquals("£A", firstToken.toString());
+
+        // verify encoding "ISO8859-1" is preserved in the Java to Ruby String conversion
+        RubyEncoding encoding = (RubyEncoding) firstToken.callMethod(context, "encoding");
+        assertEquals("ISO-8859-1", encoding.toString());
+    }
+
+    @Test
+    public void shouldNotChangeEncodingOfTokensAfterPartitioningWhenRetrieveLastFlushedToken() {
+        RubyString rubyString = RubyString.newString(RUBY, new byte[]{(byte) 0xA3, 0x0A, 0x41}); // £ character, newline, A
+        IRubyObject rubyInput = rubyString.force_encoding(context, RUBY.newString("ISO8859-1"));
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>)sut.extract(context, rubyInput);
+
+        // read the first token, the £ string
+        IRubyObject firstToken = tokens.shift(context);
+        assertEquals("£", firstToken.toString());
+
+        // flush and check that the remaining A is still encoded in ISO8859-1
+        IRubyObject lastToken = sut.flush(context);
+        assertEquals("A", lastToken.toString());
+
+        // verify encoding "ISO8859-1" is preserved in the Java to Ruby String conversion
+        RubyEncoding encoding = (RubyEncoding) lastToken.callMethod(context, "encoding");
+        assertEquals("ISO-8859-1", encoding.toString());
+    }
+
+    @Test
+    public void givenDirectFlushInvocationUTF8EncodingIsApplied() {
+        RubyString rubyString = RubyString.newString(RUBY, new byte[]{(byte) 0xA3, 0x41}); // £ character, A
+        IRubyObject rubyInput = rubyString.force_encoding(context, RUBY.newString("ISO8859-1"));
+
+        // flush and check that the remaining A is still encoded in ISO8859-1
+        IRubyObject lastToken = sut.flush(context);
+        assertEquals("", lastToken.toString());
+
+        // verify encoding "ISO8859-1" is preserved in the Java to Ruby String conversion
+        RubyEncoding encoding = (RubyEncoding) lastToken.callMethod(context, "encoding");
+        assertEquals("UTF-8", encoding.toString());
+    }
+}
\ No newline at end of file
diff --git a/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithDelimiterTest.java b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithDelimiterTest.java
new file mode 100644
index 00000000000..19872e66c3c
--- /dev/null
+++ b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithDelimiterTest.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.logstash.common;
+
+import org.jruby.RubyArray;
+import org.jruby.RubyString;
+import org.jruby.runtime.ThreadContext;
+import org.jruby.runtime.builtin.IRubyObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.logstash.RubyTestBase;
+import org.logstash.RubyUtil;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.logstash.RubyUtil.RUBY;
+
+@SuppressWarnings("unchecked")
+public final class BufferedTokenizerExtWithDelimiterTest extends RubyTestBase {
+
+    private BufferedTokenizerExt sut;
+    private ThreadContext context;
+
+    @Before
+    public void setUp() {
+        sut = new BufferedTokenizerExt(RubyUtil.RUBY, RubyUtil.BUFFERED_TOKENIZER);
+        context = RUBY.getCurrentContext();
+        IRubyObject[] args = {RubyUtil.RUBY.newString("||")};
+        sut.init(context, args);
+    }
+
+    @Test
+    public void shouldTokenizeMultipleToken() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo||b|r||"));
+
+        assertEquals(List.of("foo", "b|r"), tokens);
+    }
+
+    @Test
+    public void shouldIgnoreEmptyPayload() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString(""));
+        assertTrue(tokens.isEmpty());
+
+        tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo||bar"));
+        assertEquals(List.of("foo"), tokens);
+    }
+}
diff --git a/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithSizeLimitTest.java b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithSizeLimitTest.java
new file mode 100644
index 00000000000..9a07242369d
--- /dev/null
+++ b/logstash-core/src/test/java/org/logstash/common/BufferedTokenizerExtWithSizeLimitTest.java
@@ -0,0 +1,111 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.logstash.common;
+
+import org.jruby.RubyArray;
+import org.jruby.RubyString;
+import org.jruby.runtime.ThreadContext;
+import org.jruby.runtime.builtin.IRubyObject;
+import org.junit.Before;
+import org.junit.Test;
+import org.logstash.RubyTestBase;
+import org.logstash.RubyUtil;
+
+import java.util.List;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.Assert.*;
+import static org.logstash.RubyUtil.RUBY;
+
+@SuppressWarnings("unchecked")
+public final class BufferedTokenizerExtWithSizeLimitTest extends RubyTestBase {
+
+    private BufferedTokenizerExt sut;
+    private ThreadContext context;
+
+    @Before
+    public void setUp() {
+        sut = new BufferedTokenizerExt(RubyUtil.RUBY, RubyUtil.BUFFERED_TOKENIZER);
+        context = RUBY.getCurrentContext();
+        IRubyObject[] args = {RubyUtil.RUBY.newString("\n"), RubyUtil.RUBY.newFixnum(10)};
+        sut.init(context, args);
+    }
+
+    @Test
+    public void givenTokenWithinSizeLimitWhenExtractedThenReturnTokens() {
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("foo\nbar\n"));
+
+        assertEquals(List.of("foo", "bar"), tokens);
+    }
+
+    @Test
+    public void givenTokenExceedingSizeLimitWhenExtractedThenThrowsAnError() {
+        Exception thrownException = assertThrows(IllegalStateException.class, () -> {
+            sut.extract(context, RubyUtil.RUBY.newString("this_is_longer_than_10\nkaboom"));
+        });
+        assertThat(thrownException.getMessage(), containsString("input buffer full"));
+    }
+
+    @Test
+    public void givenExtractedThrownLimitErrorWhenFeedFreshDataThenReturnTokenStartingFromEndOfOffendingToken() {
+        Exception thrownException = assertThrows(IllegalStateException.class, () -> {
+            sut.extract(context, RubyUtil.RUBY.newString("this_is_longer_than_10\nkaboom"));
+        });
+        assertThat(thrownException.getMessage(), containsString("input buffer full"));
+
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("\nanother"));
+        assertEquals("After buffer full error should resume from the end of line", List.of("kaboom"), tokens);
+    }
+
+    @Test
+    public void givenExtractInvokedWithDifferentFramingAfterBufferFullErrorTWhenFeedFreshDataThenReturnTokenStartingFromEndOfOffendingToken() {
+        sut.extract(context, RubyUtil.RUBY.newString("aaaa"));
+
+        Exception thrownException = assertThrows(IllegalStateException.class, () -> {
+            sut.extract(context, RubyUtil.RUBY.newString("aaaaaaa"));
+        });
+        assertThat(thrownException.getMessage(), containsString("input buffer full"));
+
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("aa\nbbbb\nccc"));
+        assertEquals(List.of("bbbb"), tokens);
+    }
+
+    @Test
+    public void giveMultipleSegmentsThatGeneratesMultipleBufferFullErrorsThenIsAbleToRecoverTokenization() {
+        sut.extract(context, RubyUtil.RUBY.newString("aaaa"));
+
+        //first buffer full on 13 "a" letters
+        Exception thrownException = assertThrows(IllegalStateException.class, () -> {
+            sut.extract(context, RubyUtil.RUBY.newString("aaaaaaa"));
+        });
+        assertThat(thrownException.getMessage(), containsString("input buffer full"));
+
+        // second buffer full on 11 "b" letters
+        Exception secondThrownException = assertThrows(IllegalStateException.class, () -> {
+            sut.extract(context, RubyUtil.RUBY.newString("aa\nbbbbbbbbbbb\ncc"));
+        });
+        assertThat(secondThrownException.getMessage(), containsString("input buffer full"));
+
+        // now should resemble processing on c and d
+        RubyArray<RubyString> tokens = (RubyArray<RubyString>) sut.extract(context, RubyUtil.RUBY.newString("ccc\nddd\n"));
+        assertEquals(List.of("ccccc", "ddd"), tokens);
+    }
+}
\ No newline at end of file