Async index update thread is blocked at PDF text extraction in AEM

"aysnc-index-update-async: Extracting /content/dam/test/page1.pdf/jcr:content/renditions/original/jcr:content@jcr:data, 818992 bytes" prio=5 tid=0xe3d nid=0xffffffff runnable
java.lang.Thread.State: RUNNABLE
at java.util.regex.Pattern$BmpCharProperty.match(Pattern.java:3797)
at java.util.regex.Pattern$Curly.match0(Pattern.java:4250)
at java.util.regex.Pattern$Curly.match(Pattern.java:4234)
at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
at java.util.regex.Pattern$Curly.match0(Pattern.java:4272)
at java.util.regex.Pattern$Curly.match(Pattern.java:4234)
at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
at java.util.regex.Pattern$Curly.match0(Pattern.java:4279)
at java.util.regex.Pattern$Curly.match(Pattern.java:4234)
at java.util.regex.Pattern$Ques.match(Pattern.java:4182)
at java.util.regex.Pattern$Curly.match0(Pattern.java:4279)
at java.util.regex.Pattern$Curly.match(Pattern.java:4234)
at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
at java.util.regex.Matcher.match(Matcher.java:1270)
at java.util.regex.Matcher.matches(Matcher.java:604)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.impl.CMapResourceBuilder.parseToUnicodeMap(CMapResourceBuilder.java:371)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.PDFToUnicodeCMap.<init>(PDFToUnicodeCMap.java:317)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.PDFToUnicodeCMap.getInstance(PDFToUnicodeCMap.java:355)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.PDFFontType0.getToUnicodeCMap(PDFFontType0.java:163)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.impl.PDFFontUtils.getCharCodes(PDFFontUtils.java:1261)
at com.adobe.internal.pdftoolkit.pdf.graphics.font.PDFFontType0.getCharCodes(PDFFontType0.java:351)
at com.adobe.internal.pdftoolkit.pdf.content.processor.TextRun.getCharCodesFromFont(TextRun.java:760)